Question 718129
In (a) you invert and multiply to get
(1) {{{m(1/(m^2-4))*(m+2)}}} 
Now factor
(2) {{{(m^2-4) = (m+2)*(m-2)}}} and put into (1) and get
(3) (a) {{{m/(m-2)}}}
For (b) we need to factor all four polynomials.
First one
(4) {{{(ac +ad +bc +bd) = a(c+d) +b(c+d)}}} or
(5) {{{(ac +ad +bc +bd) = (a+b)*(c+d)}}} 
Second one
(6) {{{a^2-b^2 = (a+b)*(a-b)}}}
Third one
(7) {{{(a^3-b^3) = (a-b)*(a^2+ab+b^2)}}}
Fourth one
(8) {{{(2a^2+2ab+2b^2) = 2*(a^2+ab+b^2)}}}
Replacing each polynomial of b) with its factored form and cancelling like factors yields
(9) (b) {{{(c+d)/2}}}