a, \(2xy-x^2+49-y^2=49-\left(x^2-2xy+y^2\right)\)
\(=7^2-\left(x-y\right)^2\)
\(=\left(7-x+y\right)\left(7+x-y\right)\)
b, \(x^3+2x^2+x=x\left(x^2+2x+1\right)=x\left(x+1\right)^2\)
Bài này dễ mà. Chúc bạn học tốt.
a) \(2xy-x^2+49-y^2\)
\(=49-\left(x^2-2xy+y^2\right)\)
\(=49-\left(x-y\right)^2\)
\(=\left(7+x-y\right)\left(7-x+y\right)\)
b) \(x^3+2x^2+x\)
\(=x\left(x^2+2x+1\right)\)
\(=x\left(x+1\right)^2\)