Question 1117619
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I have no idea what the other tutor's response means.  Either I or that tutor has misread the problem....<br>
We want a number x for which
{{{(1+x)/(4+x) = 3/4}}}<br>
A solution using algebra is a good exercise in the methods of algebra:
{{{4(1+x) = 3(4+x)}}}
{{{4x+4 = 3x+12}}}
{{{x = 8}}}<br>
But probably the fastest way to an answer, if an algebraic solution is not necessary, is to look at fractions equivalent to 3/4 and find one which is in the form {{{(1+x)/(4+x)}}}<br>
{{{6/8 = (1+5)/(4+4)}}} no...
{{{9/12 = (1+8)/(4+8)}}} YES!!<br>
Solving problems informally using logical reasoning is always good mental exercise!