Factor the gcf: −6x4y5 − 15x3y2 + 9x2y3

Factor each

-6x⁴y⁵=-1*2*3*x*x*x*x*y*y*y*y*y
-15x³y²=-1*3*5*x*x*x*y*y
9x²y³=3*3*x*x*y*y*y

the number(s) common to al the groups is 3*x*x*y*y=3x²y²

remember
ab+ac=a(b+c)

3x²y²(-2x²y³)+3x²y²(-5x)+3x²y²(3y)=
3x²y²(-2x²y³-5x+3y)