Question

Help me

Answer 1

1) \(\left(2n-3\right)^2-9=\left(2n-3-3\right)\left(2n-3+3\right)\)

\(=\left(2n-6\right).2n=4n\left(n-3\right)⋮4\forall n\in Z\)

2) \(a\left(2a-3\right)-2a\left(a+1\right)=2a^2-3a-2a^2-2a\)

\(=-5a⋮5\forall a\in Z\)

Answer 2

1: \(\left(2n-3\right)^2-9\)

\(=\left(2n-3-3\right)\left(2n-3+3\right)\)

\(=2n\left(2n-6\right)\)

\(=4n\left(n-3\right)⋮4\)