Answer:
x=45
Step-by-step explanation:
The perimeter of the rectangle is 64
Answer: The required value of f(3) is 81.
Step-by-step explanation: We are given the following function :

We are to find the value of f(3).
Substituting x = 3 in equation (i), we get

Thus, the required value of f(3) is 81.
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)