Ineed work shown i have no clue how to do this and i need a good answer and you

Factorize x²+7x+12 ===> (x+3)(x+4)

Factorize x²-3x-28 ===> (x-7)(x+4)

4x + 12 can be written> 4(x+3)

Then the question could be written as follows:

 [(x+3)(x+4) / (x-7)(x+4) ] / 4(x+3) = [(x+3)(x+4) / (x-7)(x+4) ].[4(x+30]
After simplification you get 1 / 4(x-7)