Answer:
Explanation:
All of these are done exactly the same way so I will work out one of them for you, and you can follow my example to get the answers to the rest of them. I will do #5. The formula for this is
7(7 + x) = 8(8 + 13) and then solve the equation to find x:
49 + 7x = 168 and
7x = 119 so
x = 17.
Follow that pattern for each of your problems and you should be fine.