How do you multiply #(1) / (y^2 - 4) = (1) / (y + 2)#?

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Answer 1 · 2015-05-21T03:25:11

#(1) / (y^2 - 4) = (1) / (y + 2)#

We know that #color(blue)(a^2 - b^2 = (a+b)(a-b)#

so,
#(y^2 - 4) = (y+2)(y-2)#
rewriting the expression:

#(1) / ((y+2)(y-2)) = (1) / (y + 2)#

#(1) / cancel((y+2)(y-2)) = (1 . (y-2))/ cancel((y + 2)(y-2)#

# 1 = y-2#

#y =1+2 = 3#