You and your friend part at an intersection. You drive off north at a constant speed, and your friend drives east at a speed that is 10 mph higher. After 4 hours the distance between you and your friend is 368.78 miles. You have been driving at mph. (Round to the nearest mile).

Answer 1

Is your sketch a right-angled triangle with sides 4x, 4(x+10), and a hypotenuse of 368.78 ?

I see it as
(4x^2) + (4x+40)^2 = 368.78^2

use the quadratic formula to solve for x