Question

fatorando as expressoes ab +2b-3a-6 obtemos
a) (a-2).(b +3 )
b) (a+2).(b-3)
c) (a-2).(b-3)
d) (a+2). (b+3)

Answer 1

ab+2b-3a-6
trocando as posições
+a+(-3a)
=-2a=(a-2)
__________

2b+b=
3b=(3+b)
ou seja 
___
a) (a-2).(b +3 )