Total (y)
Number of hours (x)
Parts= 352
charged per hour = 58
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The general expression of installation costs
y = 58*x + 352
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total = 671
671 = 58*x + 352
58*x= 671-352
58*x= 671-352
58 x= 319
x= 5.5
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Checking
y= 58*(5.5 ) + 352
y= 319 + 352
y = 671
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The job took 5.5 h