Question

A car traveled 175 mi at a certain speed. If the

speed had been 20 mph faster, the trip could have
been made in 1 hr less time. Find the speed.​

Answer 1

The car speed: 50 mph

Explanation:

The car speed supposed to be x mph

The time spend is y hour

Xy = 175

(x + 20) * (y – 1) = 175

Xy – x + 20y -20 = 175

Xy = x – 20y + 195

175 = x – 20y + 195

X – 20y = 175 – 195 =- 20

X = 20y - 20

(20y - 20) * y = 175

20y2 - 20y -175 = 0

(2y + 5) * (10y - 35) = 0

Y = 3.5 ( answer) or y = - 2.5 (not answer, because time can’t be negative)

X = 175/3.5 = 50 mph