1.1 Factorising is the opposite of expanding brackets. In order
to find the answer, you have to find the HCF (Highest
Common Factor) of every number. In this case, the
equation is 8n+18. The HCF of 8 and 12 is 2 (*4x2=8 and
9x2=18). After you find the HCF, you put the HCF (In this
case, it's 2) on the outside of the brackets. (Refer to the *
sign for the next part) After putting 2 on the outside of the
brackets, you put 4n+9 on the inside of the brackets. So
from the equation 8n+18, it becomes 2(4n+9). Try factorising these equations :