761
-y-4y+21
2
-y +3y-7+21.
-y(y-3)-7(y-3)
-(y-3)(y+7)
763
-4b +7b-3
-4b +4b+3b-3
-4b(b-1)+3(b-1)
-(b-1)(4b-3)
765
-21v+8v+4
-21v +14v-6v+4
-7v(3v-2)-2(3v-2)
-(3v-2)(7v+2)
761
-y-4y+21
2
-y +3y-7+21.
-y(y-3)-7(y-3)
-(y-3)(y+7)
763
2
-4b +7b-3
2
-4b +4b+3b-3
-4b(b-1)+3(b-1)
-(b-1)(4b-3)
765
2
-21v+8v+4
2
-21v +14v-6v+4
-7v(3v-2)-2(3v-2)
-(3v-2)(7v+2)