\(4x^2-20xy^2+25y^4=\left(2x\right)^2-2.2x.5y^2+\left(5y^2\right)^2=\left(2x-5y^2\right)^2\)
Áp dụng hằng đẳng thức: \(\left(A-B\right)^2=A^2-2AB+B^2\)
\(4x^2-20xy^2+25y^4\)
\(=\left(2x\right)^2-2\cdot2x\cdot5y^2+\left(5y\right)^2\)
\(=\left(2x-5y\right)^2\)
\(4x^2-20xy^2+25y^4\)
\(=\left(2x\right)^2-2.2.5.xy^2+\left(5y\right)^2\)
\(=\left(2x-5y\right)^2\)
4x2-20xy2+25y4
=(2x)2-2.2x.5y2+(5y2)2
=(2x-5y2)2