câu 1:
a,x2+2x-4z2+1
=x2+2x.1+12-(2z)2
=(x+1)2-(2z)2
=(x+1-2z)(x+1+2z)
a) \(x^2+2x-4z^2+1=\left(x^2+2x+1\right)-4z^2\)
\(=\left(x+1\right)^2-\left(2z\right)^2\)
\(=\left(x+1+2z\right)\left(x+1-2z\right)\)
b) \(4x^2+4xy-16+y^2=\left(4x^2+4xy+y^2\right)-16\)
\(=\left(2x+y\right)^2-4^2\)
\(=\left(2x+y+4\right)\left(2x+y-4\right)\)
c)
áp dụng hđt đi bn động não xíu là dc thôi mak có khó lắm đâu ?
\(x^2+2x-4x^2+1\)
\(=\left(x^2+2x+1\right)-4z^2\)
\(=\left(x+1\right)^2-4z^2\)
\(=\left(x-2z+1\right)\left(x+2z+1\right)\)