Alex earns $400 per week.
He gets $150 per car (x).
"x" is the number of cars Alex has sold.
400 + 150x
If he earned $1450 last week, then
400 + 150x = 1450
First, you subtract 400 from both sides.
150x = 1050
Then divide both sides by 150.
x = 7
Therefore, Alex sold 7 cars last week.
hope this helps!