Question

Answer 1

a: \(x^2-16=x^2-4^2=\left(x-4\right)\left(x+4\right)\)

b: \(x^2-4x+4\)

\(=x^2-2\cdot x\cdot2+2^2\)

\(=\left(x-2\right)^2\)

c: \(27y^3+1=\left(3y\right)^3+1^3=\left(3y+1\right)\left(9y^2-3y+1\right)\)

d: \(\left(2x-y\right)^2-\left(2x+y\right)^2\)

\(=\left(2x-y-2x-y\right)\left(2x-y+2x+y\right)\)

\(=-2y\cdot4x=-8xy\)