Answer:
x = 8
Step-by-step explanation:
3x - 20 = 4
add 20 to both sides
3x - 20 + 20 = 4 + 20
3x = 24
divide both sides by 3
=
x = 8
Answer:-3
Step-by-step explanation:
Let the speed of the slower car = X
The speed of the faster car would be X + 15
They both traveled 3 hours and went 315 miles
Set up an equation:
3x + 3(x+15) = 315
Now solve for x:
3x + 3x +45 = 315
Simplify:
6x + 45 = 315
Subtract 45 from both sides:
6x = 270
Divide both sides by 6:
x = 270/6
x = 45
The slower car was doing 45 miles per hour.
The faster car was doing 60 miles per hour.