Question 38855This question is from textbook Beginning Algebra
: Okay, I don't even know where to begin with this one...
Subtract
5/y-7 minus 1/y+1
Please help me !! LOL
This question is from textbook Beginning Algebra
Answer by fractalier(6550)   (Show Source):
You can put this solution on YOUR website! I teach my students a method called the "criss-cross" method...
Whenever you have fractions like this you can apply a short-cut...
Goes like this...
A/B + C/D = (AD + BC) / BD
no matter what A, B, C, and D are and it works for adding or subtracting...
so from
5/(y-7) - 1/(y+1)
we criss cross and get
[5(y + 1) - (y - 7)] / [(y - 7)(y + 1)] =
5y + 5 - y + 7 / [(y - 7)(y + 1)] =
4y + 12 / [(y - 7)(y + 1)]
and we're done...
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