Question

Giúp với ạ please

Answer 1

\(1,=\left(x-y\right)\left(x+y\right)\\ 2,=\left(x-3\right)\left(x+3\right)\\ 3,=\left(2x-1\right)\left(2x+1\right)\\ 4,=\left(4-x^2\right)\left(4+x^2\right)\\ 5,=4\left(y-x\right)\left(y+x\right)\\ 5,=\left(4a-3y\right)\left(4a+3y\right)\\ 7,=\left(9-2y\right)\left(9+2y\right)\\ 8,=\left(2x-3\right)\left(2x+3\right)\\ 9,=\left(1-5a^2\right)\left(1+5a^2\right)\)