How do you multiply (4a^2 - 1) /( a^2 - 4) * (a - 2)/(2a - 1)?

1 Answer
May 23, 2015

Before multiplying we can factor the two quadratic equations you got there:

4a^2-1=0
4a^2=1
a^2=1/4
a^2=+-1/2, thus the factors are (2a-1)=0 and (2a+1)=0

a^2-4=0
a^2=4
a=+-2, thus the factors are (a-2)=0 and (a+2)=0

Rewriting:

(cancel(2a-1)(2a+1))/(cancel(a-2)(a+2))cancel(a-2)/cancel(2a-1)

Final answer: (2a+1)/(a+2)