
William W. answered 11/25/22
Math and science made easy - learn from a retired engineer
This is just an exercise in getting common denominators, adding fractions, and dividing fractions.
Working only with the numerator:
The common denominator is (x - y)(y). Multiply y/(x - y) by y/y and multiply (x + y)/y by (x - y)/(x - y).
It becomes:
y2/[(x - y)(y)] + [(x + y)(x - y)]/[(x - y)(y)]
y2/[(x - y)(y)] + (x2 - y2)/[(x - y)(y)]
(y2 + x2 - y2)/[(x - y)(y)]
x2/[(x - y)(y)]
Working only with the denominator:
The common denominator is (x)(x + y). Multiply (x - y/x by (x + y)/(x + y) and multiply y/(x + y) by x/x.
It becomes:
[(x - y)(x + y)]/[(x)(x + y)] + xy/[(x)(x + y)]
(x2 - y2)/[(x)(x + y)] + xy/[(x)(x + y)]
(x2 + xy - y2)/[(x)(x + y)]
Now, you are dividing 2 fractions so keep the top as is, change the problem to multiplication, and flip the bottom one:
x2/[(x - y)(y)] • [(x)(x + y)]/(x2 + xy - y2) which you can multiply out if desired:
[x3(x + y)]/[(x - y)(y)(x2 + xy - y2)]
(x4 + x3y)/[(xy - y2)(x2 + xy - y2)]
(x4 + x3y)/(x3y - 2xy3 - y4)