Answer:
The answer is .393. Hope this helps.
Whenever a number is beside a parenthesis without a sign it means multiplication. So you would use PEMDAS work in parenthesis then exponents, multiplication (from left to right) addition and subtraction (from left to right). so you would add 20+3 and get 23 then multiply that by -5 to get -115 as your answer.
50 + 20h = 100 + 10h
20h - 10h = 100 - 50
10h = 50
h = 50/10
h = 5 <== they will charge the same at 5 hrs
