Answer:
The answer is 4r² – 9
Denise answer is correct.
Step-by-step explanation:
One of the methods of solving the given equation [(2r – 3)(2r + 3)] is the FOIL method
Using the FOIL method (Used for multiplying binomials)
F stands for first
O stands for outer
I stands for inner
L stands for last
In this method, it means we will first multiply the first terms followed by multiplying the outer term, then multiplying the inner terms and finally, the last terms.
So, for the equation (2r – 3)(2r + 3)
First : (2r)(2r) = 4r²
Outer : (2r)(+3) = 6r
Inner : (–3)(2r) = – 6r
Last : (–3)(+3) = – 9
Adding the results we get
4r² + 6r – 6r – 9 (+6r and – 6r cancels out)
= 4r² – 9
∴ (2r – 3)(2r + 3) = 4r² – 9
Hence, Denise answer is correct
