
Adam S. answered 08/31/16
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The problem can be expressed as two equations in two unknowns.
X = first trail mix in pounds
Y = second trail mix in pounds
1)The 38% trail mix is mixed with the 62% trail mix to produce a 50% trail mix of 144 lbs.
2)The weight of the two trail mixes adds to 144 lbs.
1) 0.38X + 0.62Y = 0.50(144)
2) X + Y = 144
multiply equation 2 by 0.62, then subtract equation 2 from equation 1.
1) 0.38X + 0.62Y = 0.50(144)
2)- 0.62(X + Y) = -0.62(144)
0.38X - 0.62X = 0.50(144) - 0.62(144)
-0.24X = -0.12(144)
X = 0.12(144)/0.24 = 72 lbs.