Question 1040326
Let's think in reverse. We want to end up with {{{(x-y)/y}}}. Let's break this up and see how we can get to {{{x/y}}}.



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{{{(x-y)/y}}} Start with the expression we want to end up with



{{{x/y-y/y}}} Break up the fraction



{{{x/y-1}}} Simplify



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So hopefully you can see that simply subtracting 1 from {{{x/y}}} will help us get to {{{x/y-y/y}}} which turns into {{{(x-y)/y}}}



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So let's apply this to the problem to get



{{{x/y = m}}} Given



{{{x/y-1 = m-1}}} Subtract 1 from both sides



{{{x/y-y/y = m-1}}} Turn the '1' on the left side into {{{y/y}}} (y is nonzero)



{{{(x-y)/y = m-1}}} Combine the fractions



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So {{{(x-y)/y}}} is equal to {{{m-1}}} where it is given that {{{x/y = m}}}