Use Pythagoras:
x² = (8.5)² + (5)²
x = √[(8.5)² + (5)²]
3x + 4(x + 1) = 67
7x + 4 = 67
7x = 67-4 = 63
x = 9
The smaller integer is 9.
Answer:
The number of cars that brings the same profit is 9 and 0
Step-by-step explanation:
Given

Required
Determine the possible values of x

Subtract 5x from both sides


Factorize

Split the equation
or 
or 
<em>Hence, the number of cars that brings the same profit is 9 and 0</em>