57 miles because of they are driving 38 miles per hour that means in 1 hour they drive 38 miles. So if they drove for an hour and a half you take 38 and half of 38( which is 15) and you add them together.
The formulas:

Expand the expression:

Plug the values into the expression:
Sub f(x)=1 into equation
1=-5x-4
5=-5x
x=-1
We assume that we need to simplify the expression in two different ways.
Answer:
One way: Raise both, the numerator and denominator, to the third power, and then simplify the expression.
Second way: Simplify the terms inside parentheses, and then raise the result to the third power.
The result of both ways is the same: 
Step-by-step explanation:
<em>One way</em>
Raise both, the numerator and denominator, to the third power, and then simplify the expression:





This is the first simplification.
<em>Second way</em>
Simplify the terms inside parentheses, and then raise the result to the third power.






or
.