Answer:
Step-by-step explanation:(2^2+b)(a^2-9b)
This means to expand the brackets
2^2=4
(4+b)(a^2-9b)
Look at the first bracket
The first term is 4 and is multiplied by the second bracket
4(a^2-9b) expand the brackets
=4a^2-36ab
and
The second term of the first bracket is:
b(a^2-9b)=a^2(b)-9b^2
We now add the two expanded brackets together to get the following:
=4a^2-36ab+a^2-9b^2
cannot be simplified any further