We can make an equation from this. Our intial value is 150 for parts, and he works for 52 dollars an hour. We can define <em /><em>h</em> for hours and <em /><em>c</em> for total cost. Therefore, we have: c = 150 + 52h. We can set this equal to 306 dollars, as that's the given total cost: 306 = 150 + 52h Subtract 150 from both sides: 52h = 156 Divide both sides by 2: h = 3 He worked 3 hours. hope this helped!