Question 77154
3y/y^2+5y+4
plus
2y/y^2-1=
------------
3y/[(y+4)(y+1)] + [2y/[(y+1)(y-1)]

Least common denominator is (y+4)(y+1)(y-1)

=3y(y-1)/lcd + 2y(y+4)/lcd

=[3y^2-3y+2y^2+8y]/lcd

=[5y^2+5y]/lcd

=[5y(y+1)]/lcd

=5y/[(y+4)(y-1)]

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Cheers,
Stan H.