When is it best to solve a system of equations using substitution?

Answer:

4

Step-by-step explanation:

6 - 2 = 4

Answer:

4

Step-by-step explanation:

Ciara is not my friend but she's my sister

Answer: See below

Step-by-step explanation:

Isolate x for x-2y+2z=9

3x=9+2y

[tex]x=\frac{9+2y}{3}[/tex]....(1)

Substitute (1) into the 2nd equation

[tex]\begin{bmatrix}-\frac{9+2y}{3}+3y=-4\\ 2\cdot \frac{9+2y}{3}-5y+3z=16\end{bmatrix}[/tex]

[tex]\frac{3\left(-9+7y\right)}{3}=3\left(-4\right)[/tex]

7y=-3

y=-3/7

Substitute y=-3/7

[tex]\begin{bmatrix}3z+\frac{18-11\left(-\frac{3}{7}\right)}{3}=16\end{bmatrix}[/tex]

[tex]\begin{bmatrix}3z+\frac{53}{7}=16\end{bmatrix}[/tex]

Isolate z by substituting it

[tex]3z+\frac{53}{7}=16[/tex]

[tex]\frac{3z}{3}=\frac{\frac{59}{7}}{3}[/tex]

[tex]z=\frac{59}{21}[/tex]

For x =9+2y/3 substitute z=59/21 and y=-3/7

[tex]x=\frac{9+2\left(-\frac{3}{7}\right)}{3}[/tex]

[tex]x=\frac{19}{7}[/tex]

[tex]x=\frac{19}{7},\:z=\frac{59}{21},\:y=-\frac{3}{7}[/tex]

Answer:

(1, - 1, 3 )

Step-by-step explanation:

x - 2y + 2z = 9 → (1)

- x + 3y = - 4 → (2)

2x - 5y + 3z = 16 → (3)

Add (1) and (2) term by term to eliminate x

y + 2z = 5 → (4)

Multiply (2) by 2

- 2x + 6y = - 8 → (5)

Add (3) and (5) term by term to eliminate x

y + 3z = 8 → (6)

Subtract (6) from (4) term by term to eliminate y

- z = - 3 ( multiply both sides by - 1 )

z = 3

Substitute z = 3 into (4)

y + 2(3) = 5

y + 6 = 5 ( subtract 6 from both sides )

y = - 1

Substitute y = - 1, z = 3 into (1) and solve for x

x - 2(- 1) + 2(3) = 9

x + 2 + 6 = 9

x + 8 = 9 ( subtract 8 from both sides )

x = 1

solution is (1, - 1, 3 )

Answer:

1/4

Step-by-step explanation:

Divide both the numerator and denominator by the GCD 9 ÷ 9

36 ÷ 9

Reduced fraction: 1/4 Therefore, 9/36 simplified to lowest terms is 1/4.

Answer:

beyond the words of a constitution or statute to consider the broader societal implications of their decisions.

Step-by-step explanation:

Answer:

answer is x=15

AM=18

AB=4

1=2

2=10

3=20

Answer:

A

rise⇵ over run ⇄

the rise is -6 the run is 3

Step-by-step explanation:

18.

the last one.

-4.9t² + 24.5t + 117.6 = 0

the ball starts at 117.6 meters height. then, during the first seconds the thrust upwards is adding height, until finally, with more and more seconds passing, gravity will win with a vengeance and pulls the ball down faster and faster than any other force in any other direction.

19.

the general solution for a quadratic equation

y = ax² + bx + c

is

x = (-b ± sqrt(b² - 4ac))/(2a)

in our case

x = t

a = -4.9

b = 24.5

c = 117.6

t = (-24.5 ± sqrt(600.25 - -4×4.9×117.6))/-9.8 =

= (-24.5 ± sqrt(600.25 + 2304.96))/-9.8 =

= (-24.5 ± sqrt(2905.21))/-9.8 = (-24.5 ± 53.9)/-9.8

t1 = (-24.5 + 53.9)/-9.8 = -3

t2 = (-24.5 - 53.9)/-9.8 = 8

a negative time does not make any sense, so the real solution is : the ball reached the ground after 8 seconds.

20.

now the equation is

-4.9t² + 24.5t + 117.6 = 49

but this is quickly transformed again into a "= 0" equation :

-4.9t² + 24.5t + 68.6 = 0

t = (-24.5 ± sqrt(600.25 - -4×4.9×68.6))/-9.8 =

= (-24.5 ± sqrt(600.25 + 1344.56))/-9.8 =

= (-24.5 ± sqrt(1944.81))/-9.8 = (-24.5 ± 44.1)/-9.8

t1 = (-24.5 + 44.1)/-9.8 = -2

t2 = (-24.5 - 44.1)/-9.8 = 7

again, negative time does not make sense.

the ball will be at 49 m height after 7 seconds.

-7/40

/////

I honestly didn't know how to do this one. But thats the correct answer.

The solution of the mathematical expressions will be 0.175.

What is Number system?

A system of writing to express the number is called number system.

Given that;

The mathematical expressions are,

⇒ [ 2 - | - 1/4 - 2 (-3/5) | ] ÷ -6

Now,

Solve the mathematical expression as;

⇒  [ 2 - | - 1/4 - 2 (-3/5) | ] ÷ -6

Using the BODMAS rule to solve the expressions as;

⇒ [ 2 - | - 1/4 - 2 (-3/5) | ] ÷ -6

⇒ [ 2 - | - 1/4 + 6/5 | ÷ -6

⇒ [ 2 - 19/20 ] ÷ -6

⇒  [ 21/20] ÷ -6

⇒ 21/20 x 1/-6

⇒ - 7 / 40

Therefore,

The solution of the mathematical expressions will be 0.175.

Learn more about the mathematical expression visit:

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Answer:

4

Step-by-step explanation:

Answer:

3.95 ≈ 4

Step-by-step explanation:

A whole number refers to a whole integer, meaning there can be no decimals or fractions. Follow the rule 4 and below to round down, and 5 and above to round up.

Answer:

A

Step-by-step explanation:

They both equal 2(x+y+1)

Answer:

8

Step-by-step explanation:

whatever was done to y needs to be done to  x.

in this case (y) was 2x so you need to 2x (x) making 4 into 8

Answer:

shoe = 5, clock = 3, rope = 13

Step-by-step explanation:

hope this helped :) i just used guess and check knowing that the shoe is clock+2 hahah

Answer:

Enter a value for a so that the system of equations shown has infinitely many solutions.

y = −5x + 9y =    ax + 9

Step-by-step explanation:

Answer:

check online for more information

Answer:

Check online for more informations.

Answer:

x + y = 11

Step-by-step explanation:

You would need to substitute the numbers into the expression.

Evaluate means that we need to work out what the answer would be.

x + y is equivalent to 9 - - 2.

- - is equivalent to +.

Therefore you would do 9 + 2, which equals 11.

Hope this helps :)

Answer:

Pronator??

Step-by-step explanation:

Answer:

Step-by-step explanation:

You have to draw sets:

[tex]y<\dfrac{1}{2}x-1\qquad(1)\\\\y\leq-3x+2\qquad(2)[/tex]

in the coordinates system.

[tex]y=\dfrac{1}{2}x-1\\\\x=0\to y=\dfrac{1}{2}\cdot0-1=-1\to(0,\ -1)\\\\x=2\to y=\dfrac{1}{2}\cdot2-1=1-1=0\to(2,\ 0)[/tex]

dashed line

mark the region below the line

[tex]y=-3x+2\\\\x=0\to y=-3\cdot0+2=2\to(0,\ 2)\\\\x=1\to y=-3\cdot1+2=-3+2=-1\to(1,\ -1)[/tex]

solid line

mark the region below the line

Read points on the common region (look at the picture).

Answer:

Perimeter of ΔABC: [tex]\frac{27}{2}[/tex] + [tex]\frac{9}{2} * \sqrt6[/tex] units

Area of ΔABC: [tex]\frac{81}{8}*\sqrt3 + \frac{243}{8}[/tex] units

Skills required: HS Geo, Special Triangles

Step-by-step explanation:

1) The best option is to break down this triangle. Let's draw an altitude from Point B down to Segment AC. The point from the altitude that intersects AC is Point D. BD is the height of our triangle, AC is the base.

2) Angle A is 60 degrees, and since Angle BDA is 90 degrees, Angle ABD is 30 degrees. We can use the 30-60-90 degree right triangle property for the triangle BDA.

AB is 9 units, and it is opposite the 90 degree angle. This means that [tex]2x=9, x = \frac{9}{2}[/tex] ==> This then means that AD, the segment opposite the 30 degree angle in this triangle is [tex]\frac{9}{2}[/tex] units. Segment BD (the height) is [tex]\frac{9}{2} * \sqrt3[/tex].

3) Angle C is 45 degrees, and Angle BDC is 90 degrees, which means that Angle CBD is 45 degrees. We can use the 45-45-90 degree right triangle property for the triangle BCD.

BD is [tex]\frac{9}{2} * \sqrt3[/tex], which means DC is the same. BC, which is the hypotenuse is BD multiplied by square-root-2, which is [tex]\frac{9}{2} * \sqrt6[/tex].

4) Area is [tex]\frac{1}{2}*b*h[/tex], the base (b) is AC (which is [tex]\frac{9}{2}+\frac{9}{2}*\sqrt3[/tex]), the height is BD ([tex]\frac{9}{2}*\sqrt3[/tex]). When multiple you will get [tex]\frac{81}{4}*\sqrt3 + \frac{243}{4}[/tex], then this multiplied by 1/2 is

[tex]\frac{81}{8}*\sqrt3 + \frac{243}{8}[/tex] <--> this is the area!

5) Perimeter is just the sum of all side: 9 + [tex]\frac{9}{2}[/tex] + [tex]\frac{9}{2} * \sqrt6[/tex] = [tex]\frac{27}{2}[/tex] + [tex]\frac{9}{2} * \sqrt6[/tex] unit

Answer:

5 => 2

6 => 3

7 => 4

8 => 5

9 => 6

Answer:

2,3,4,5,6

Step-by-step explanation:

y = 5 - 3 = 2

y = 6 - 3 = 3

y = 7 - 3 = 4

y = 8 - 3 = 5

y = 9 - 3 = 6

Answer:

43°

Step-by-step explanation:

Answer:

A-   43

Step-by-step explanation:

ed2022

Answer:

x = 22

Step-by-step explanation:

4x + 28 = 116 (corresponding angles are equal when two lines are parallel)

4x = 88

x = 22

Corresponding angles must be equal

[tex]\\ \tt\hookrightarrow 4x+28=116[/tex]

[tex]\\ \tt\hookrightarrow 4x=116-28[/tex]

[tex]\\ \tt\hookrightarrow 4x=88[/tex]

[tex]\\ \tt\hookrightarrow x=22[/tex]

Answer:

x (upper level) = 12,000 tickets

Step-by-step explanation:

Firstly, let's convert this gibberish text into the information we want. :D

Total amount of people = 52,000

Main floor tickets = $25 each

Total: $1,144,000

Let the amount of people who brought upper level tickets be x and main floor tickets be y. (assumming 1 ticket = 1 person)

Thus, we come up with this simultaneous equation:

[tex]12x + 25y = 1,144,000\\x + y = 52,000[/tex]

The first equation finds the price of the ticket, while the second is the amount of people.

x (upper level) = 12,000

y = 40,000

Hope this helps! :)

Answer: 49

Step-by-step explanation:

Answer:

uhhh maybe ( x + 2 ) = y

Step-by-step explanation:

i dont know im on break and I don forgot how to do this

Answer:

648

Step-by-step explanation:

Running this in Python, with the code as follows,

import math

cur_numbers = [0] * 3

num = 0

for i in range(100, 1000):

   cur_numbers[2] = i % 10

   i = math.floor(i/10)

   cur_numbers[1] = i % 10

   i = math.floor(i/10)

   cur_numbers[0] = i % 10

   if(len(set(cur_numbers)) == 3):

       num += 1

       print(cur_numbers)

print(num), we get 648 as our answer.

Another way to solve this is as follows:

There are 9 possibilities for the hundreds digit (1-9). Then, there are 10 possibilities for the tens digit, but we subtract 1 because it can't be the 1 same digit as the hundreds digit. For the ones digit, there are 10 possibilities, but we subtract 1 because it can't be the same as the hundreds digit and another 1 because it can't be the same as the tens digit. Multiplying these out, we have

9 possibilities for the hundreds digit x 9 possibilities for the tens digit x 8 possibilities for the ones digit  = 648

The number of bacterial population after 5 hours is; 816

N(t) = N_o(1 + r)^(t)

Where;

N(t) is number of bacteria after t hours

N_o is number of bacteria initially

r is growth rate

t is time

N_o = 480

r = 11.2% = 0.112

t = 5

N(5) = 480(1 + 0.112)^(5)

N(5) = 816.14

Read more about exponential growth at; https://brainly.com/question/15316908