Question
You ran out of paint and primer while changing the color tone in your new house. You had already purchased 4 gallons of paint and 9 gallons of primer for a total cost of $275. Back to the paint shop, added 3 more gallons of paint and 5 gallons of primer for $180. Find the cost per gallon for the paint and the pine.
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Answer to a math question You ran out of paint and primer while changing the color tone in your new house. You had already purchased 4 gallons of paint and 9 gallons of primer for a total cost of $275. Back to the paint shop, added 3 more gallons of paint and 5 gallons of primer for $180. Find the cost per gallon for the paint and the pine.
Hermann
4.6126 Answers
let cost of paint be x and cost of primer be y
4x + 9y = 275
3x + 5y = 180
muliply the 1st equation with -3 and the 2nd equation by 4
-12x - 27y = -825
12x + 20y = 720
add both equations
-7y = -105
y = 15
substitute to equation 1
4x + 9*15 = 275
4x = 275 - 135
4x = 140
x = 35
therefore cost per gallon of paint is 35 while cost per gallon of primer is 15.
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