a,\(x^2-9+\left(x-3\right)^2\)
\(=\left(x+3\right)\left(x-3\right)+\left(x-3\right)^2\)
\(=\left(x+3+x-3\right)\left(x-3\right)\)
\(=2x\left(x-3\right)\)
b,\(x^3-4x^2+4x-xy^2\)
\(=x\left(x^2-4x+4-y^2\right)\)
\(=x\left[(x-2)^2-y^2\right]\)
\(=x\left(x-2+y\right)\left(x-2-y\right)\)
c,\(3x^2-7x-10\)
\(=3x^2-10x+3x-10\)
\(=\left(3x^2+3x\right)+\left(-10x-10\right)\)
\(=3x\left(x+1\right)-10\left(x+1\right)\)
\(=\left(3x-10\right)\left(x+1\right)\)
d,\(5x^3-5x^2y-10x^2+10xy\)
\(=\left(5x^3-5x^2y\right)+\left(-10x^2+10xy\right)\)
\(=5x^2\left(x-y\right)-10x\left(x-y\right)\)
\(=\left(5x^2-10x\right)\left(x-y\right)\)
\(a,x^2-9+\left(x-3\right)^2\)
\(=x^2-9+x^2-6x+9\)
\(=2x^2-6x\)
\(b,x^34x^2+4x-xy^2\)
\(=x\left(x^2-4x+4-y^2\right)\)
\(=x\left[\left(x-2\right)^2-y^2\right]\)
\(=x\left(x-2-y\right)\left(x-2+y\right)\)
\(c,3x^2-7x-10\)
\(=3x^2+3x-10-10\)
\(=3x\left(x+1\right)-10\left(x+1\right)\)
\(=\left(3x-10\right)\left(x+1\right)\)
