Expand and simplify: (P127)

a) ( +8) ( -1) – ( -4)

=6- + -8-(21-)

=-2 + -21 +

=-23+

Firstly, when we solve this type of questions, we need to find the like terms becasue when adding/ substraction, the coefficients are combined when the radicands are the same. For example, in this question, like terms are , and ( becasue you can find they all have , and that means we need to think of a way to combine them together to get a simplified answer. Secondly, do the calculation carefully and be aware of the like terms. Final step is to check you answer is already simplified or not.