Answer:
Step-by-step explanation:
distance = rate times time, so
distance
time = --------------
rate
Here the distance is 40 km and the rate is x. Then
40 km
time = -------------- = (40/x) hr
x km/hr
If the speed is reduced by 2 km/hr, we get:
40 km 40 km 40
time = ------------------------------- or time = ----------------------- = --------- hr
(x km/hr - 2 km/hr) (x - 2) (km/hr) x - 2
The difference between the times is:
40 40
-------- - --------- = 1 hr Solve this for the original speed, x
x - 2 x
40x - 40x + 80 80
----------------------- = 1 hr or ------------ = 1 or 80 = x^2 - 2x
x(x - 2) x(x - 2)
Rewriting this in standard quadratic form: x^2 - 2x - 80 = 0
Here a = 1, b = -2 and c = -80, and so the discriminant b^2 - 4ac is:
(-2)^2 - 4(1)(-80) = 324
The solutions are:
-(-2) ± √324 2 ± 18
x = -------------------- = ------------ = 1 ± 9, or 10 (discard the other root)
2 2
The original speed was 10 km/hr
the answer is 10 km/hr.
Please anyone help me The measure of an angle is five times the measure of its supplementary angle. What is the measure of each angle?
Answer:
150 and 30
Step-by-step explanation:
Hello!
Supplementary angles are angles that when added up equal 180
Which can be shown by
x + x = 180
Since one has to be 5 times bigger we put a 5 in front of one of the x's
5x + x = 180
5x is an angle and x is the other
Now we solve for x
5x + x = 180
Combine like terms
6x = 180
Divide by 6
x = 30
Now we put that into each angle
5(30) = 150
30
The answer is 150 and 30
Hope this Helps!
Hello!
Answer:
Each angle; the answer is 30 & 150
Step-by-step explanation:
So let say that the supplement is ‘X’.... You want to find the angle of 5x
Therefore, 6x=180 (X=30)
Since we found out one angle out which is 30.
Now you find 5x.
5x30 and you will get 150.
So the angles of each is “30” and “150”.
Hope this helps!
By, Cherry