Let the rate of one mechanic = x
Let the other's rate= 145 - x
So we have
20x + 5 ( 145 - x) = 2150 simplify
20x + 725 - 5x = 2150
15x + 725 = 2150
15x = 2150 - 725
15x = 1425 divide both sides by 15
x = 1425 / 15 = $95
145 - 95 = $50
The two rates were $ 95 and $ 50