Question

  Giải giúp với

Answer 1

a) Ta có:
\(VT=x^2+4\\ =\left(x^2+4x+4\right)-4x\\ =\left(x+2\right)^2-4x=VP\)

b) Ta có: 

\(VT=\left(x-y\right)^2=\left(x+y\right)^2-4xy\\ =x^2+2xy+y^2-4xy\\ =x^2-2xy+y^2\\ =\left(x-y\right)^2=VP\)

Answer 2

a) 

Ta có:\(VP:\left(x+2\right)^2-4x\)

\(=x^2+4x+4-4x\)

\(=x^4+4=VT\)

b) 

Ta có:\(VP=\left(x+y\right)^2-4xy\)

\(=x^2+2xy+y^2-4xy\)

\(=x^2-2xy+y^2\)

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