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Question 262681: If x/y=4 and y is not '0' what % of x is 2x-y
(a)150% (b)175% (c)200% (d)250%
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! x/y = 4 and y is not = 0.
multiply both sides of this equation by y to get:
x = 4*y
divide both sides of this equation by 4 to get:
y = x/4
question is:
what percent of x is 2x-y
substitute x/4 for y in the expression 2x-y to get:
2x - x/4
multiply 2x by 4/4 to make the expression equal to:
8x/4 - x/4
combine common denominators to get:
(8x-x)/4
simplify to get:
7x/4
the question is:
what percent of x is 2x-y
since 2x-y = 7x/4, then:
take 7x/4 and divide it by x to get:
(7x/4)/x = 7x/4 * 1/x = 7x/4x = 7/4.
7/4 = 1.75 * 100% = 175%.
your answer is selection b which is 175%.
to see this easier, put it into numbers.
the question was:
what percent of x is 2x-y if x/y = 4 (y not 0).
start with x/y = 4.
multiply both sides by y to get 4*y = x
if x = 20, then 4*y = 20 making y = 5 because 4 * 5 = 20
you have:
x = 20
y = 5
the question is what percent of x is 2x-y.
x is 20
2x-y = 2*20 - 5 = 40-5 = 35
35/20 = 1.75 * 100% = 175%.
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