Just add 32 + 33 = 65. 65 would be the minimum amount.
The correct equation is 8.7 + b = 54.6
because it is given that measure of side a is 8.7cm, in all other equations the values of a is different.
from the first equation we can find the value of b, that is
b = 54.6 - 8.7 = 45.9
so, value of b is 45.9cm
So first, you want to open the parenthesis here.
So, to do that, first look at the symbol before the parenthesis.
In this case it's a -.
So when it's a -, reverse the symbol inside the parenthesis. (This is because if you don't you're subtracting 2x and then adding 8, when really you're subtracting both 2x and 8.)
So,
9x - 2x - 8
Or simplified,
7x - 8
