Answer:
something like what? what do you mean?
Step-by-step explanation:
Mathematical equation -
20 + 0.50x = ?
X is the placeholder which in this case equals months
But in this case you want to look for form month three to month 18 (which is 15 months) so three months went by so the equation is
$61.50(being the three months already)
(20+(0.50*15))+61.50=?

Always divide low by high then multiply by 100 to get your answer:
- - Answer: 25%
I think it’s $19.14 someone please correct me if I’m wrong.