Question 191325
Just write what it says:
:
The denominator of fraction is 4 more than its numerator.
d = n + 4
: 
Taking square of this fraction we get a new fraction.
n^2/d^2
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The difference between the denominator and numerator of the new fraction is 40.
d^2 - n^2 = 40
:
 Find the fraction.
Substitute (n+4) for d in the above equation
(n+4)^2 - n^2 = 40
FOIL
n^2 + 8n + 16 - n^2 = 40
:
8n = 40 - 16
:
8n = 24
n = {{{24/8}}}
n = 3
then
d = 3 + 4
d = 7
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{{{3/7}}} is the fraction
:
:
Check:
9/49 is the new fraction, difference of 40