Ineed with this equation. 9q - 14 + 3(q - 8) = 7 i looked it up and the answer was 3.75, however i don't understand how it works.

you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.

a and c

for infinitely many solutions we require both left and right sides to be equal

distribute and simplify

a

14 - 8x = 20 - 8x - 6 = 14 - 8x ← both sides equal so infinite solutions

b

6x - 54 = 6x - 54 + x = 7x - 54 ← not equal

c

4x + 16 = 4x + 10 + 6 = 4x + 16 ← both sides equal so infinite solutions

d

5x - 40 + 10 = 5x + 10

5x - 30 = 5x + 10 ← not equal