Factorise
ab2+(a-1)b-1
The expression given to us is ab2+(a-1)b-1
Thus,
ab2+(a-1)b-1 = ab2+ab-b-1
= (ab2+ab)-1(b+1), grouping the terms together
= ab(b+1)-1(b+1), taking "ab" common
= (ab-1)(b+1), taking (b+1) common from both terms.
Thus the required factors are (ab-1)(b+1).
Thus,
ab2+(a-1)b-1 = ab2+ab-b-1
= (ab2+ab)-1(b+1), grouping the terms together
= ab(b+1)-1(b+1), taking "ab" common
= (ab-1)(b+1), taking (b+1) common from both terms.
Thus the required factors are (ab-1)(b+1).