Answer
$a. \quad x=40.$
When 40 miles are driven, both companies charge an equal amount.
$b. \quad y\approx 55$.
When 40 miles are driven, both companies charge about ${{\$}} 55$.
$c. \quad y=54.$
The actual charge by both companies when 40 miles are driven,
is ${{\$}} 54.$
Work Step by Step
Each graph contains points (x,y), where
y is the amount charged by the company when x miles are driven.
$a.$
The intersection point has x-coordinate $x=40.$
When 40 miles are driven, both companies charge an equal amount.
$b.$
From the graph, it is reasonable to estimate $y=55$.
When 40 miles are driven, both companies charge ${{\$}} 55$.
$c.$
Solving for y in each of the equations, when $x=40$:
$\left[\begin{array}{lllll}
y=0.35(40)+40 & & | & y=0.45(40)+36 & \\
y=14+40 & & | & y=18+36 & \\
y=54 & & | & y=54 &
\end{array}\right]$
The actual charge by both companies when 40 miles are driven,
is ${{\$}} 54.$
