a)\(2x^2-3x-2\)
\(=2x^2+x-4x-2\)
\(=x\left(2x+1\right)-2\left(2x+1\right)\)
\(=\left(x-2\right)\left(2x+1\right)\)
b)\(3x^2+x-2\)
\(=3x^2-2x+3x-2\)
\(=x\left(3x-2\right)+\left(3x-2\right)\)
\(=\left(x+1\right)\left(3x-2\right)\)
c)\(4x^2-7x-2\)
\(=4x^2+x-8x-2\)
\(=x\left(4x+1\right)-2\left(4x+1\right)\)
\(=\left(x-2\right)\left(4x+1\right)\)
d)\(4x^2+5x-6\)
\(=4x^2-3x+8x-6\)
\(=x\left(4x-3\right)+2\left(4x-3\right)\)
\(=\left(x+2\right)\left(4x-3\right)\)
ý 1:
2x2-3x-2=2x2-4x+x-2=2x(x-2)+(x-2)=(x-2)(2x+1)
ý 2:
3x2+x-2=3x2+3x-2x-2=(3x2+3x)-(2x+2)=3x(x+1)-2(x+1)=(x+1)(3x-2)
ý 3:
4x2-7x-2=4x2-8x+x-2=(4x2-8x)+(x-2)=4x(x-2)+(x-2)=(x-2)(4x+1)
ý 4:
4x2+5x-6=4x2+8x-3x-6=(4x2+8x)-(3x+6)=4x(x+2)-3(x+2)=(x+2)(4x-3)
