Alright, this is a lot.
This start with the first question (3)
Find the product of 5(18) and 5(18) = 90
To get that is 5(18) = (5 x 18 = 90)
So now we have to do the math for both A and B and find out which one is 90
A 5(10+8) : 10 + 8 = 18 so (a) = 5(18)
B 5(20-2) : 20 - 2 = 18 also well
I think (a) would be your best bet. For question (3)
Alright question 4
(a) = 8x + 40
(b) = 4y - 36
(c) = -6n - 18
(d) = 7x + 7
(e) = 30-10x
(f) = 4x + 2
Hope this helps in any way. Tell me if It's right