Question

How do you express `3/((1 + x)(1 - 2x))` in partial fractions?

Answer 1

`3/((1+x)(1-2x)) = 1/(1+x) +2/(1-2x)`

Explanation:

`3/((1+x)(1-2x)) = A/(1+x) +B/(1-2x)`

`3=A(1-2x)+B((1+x)`

`3=A-2Ax+B+Bx`

`A+B=3, -2A+B=0`

`B=3-A->-2A+3-A=0->-3A+3=0`

`-3A=-3,A=1,B=2`

`3/((1+x)(1-2x)) = 1/(1+x) +2/(1-2x)`