a ) \(3x^2-7x+2\)
= \(3x^2-6x-x+2\)
= \(3x\left(x-2\right)-\left(x-2\right)\)
= \(\left(x-2\right)\left(3x-1\right)\)
b ) \(a\left(x^2+1\right)-x\left(a^2+1\right)\)
= \(ax\left(x-a\right)-\left(x-a\right)\)
= \(\left(x-a\right)\left(ax-1\right)\)
Chúc bạn học tốt !!!