Question 1142695
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A coffee merchant blended coffee worth 93 cents a pound with coffee worth $1.20 a pound. The mixture of 30 pounds was valued by him at $1.02 a pound. How many pounds of each grade did he use? 
Please, if possible, use a model for me. 
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L = 0.93 dollars per pound
H = 1.02 dollars per pound
T = 1.02
M = 30 pounds
y,  unknown amount in pounds for the H coffee
M-y, unknown amount of L coffee


{{{highlight_green(L(M-y)+Hy=TM)}}}
Solve for y, and evaluate M-y.


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{{{LM-Ly+Hy=TM}}}

{{{Hy-Ly+LM=TM}}}

{{{(H-L)y=TM-LM}}}

{{{highlight(y=(TM-LM)/(H-L))}}}------substitute the given values here and evaluate y.