Question

c/m các đẳng thức sau:

Answer 1

e: Ta có: \(\left(2x+3\right)\left(2x-3\right)\left(4x^2+9\right)\)

\(=\left(4x^2-9\right)\left(4x^2+9\right)\)

\(=16x^4-81\)

f: Ta có: \(\left(a+b\right)^2-\left(a-b\right)^2\)

\(=a^2+2ab+b^2-a^2+2ab-b^2\)

=4ab