Answer:
x = 37
Step-by-step explanation:
Power Theorem: 10 x (10 + 26) = 8 x (8 + x)
360 = 8 x (8 + x)
8 + x = 45
x = 37
110% of 90 is:
90*1.10 = 99
The given formula 
Solve for y means we have to make y alone
\\
Add -10 on both sides, we get

As there is multiplication sign between r and y so to solve for y, divide both side by r

4.2 hours x .4 gallons per hour = 1.68 gallons