It can hold 9 ounces of oil and 90 ounces of gasoline cause if you take 10 oz of gas and times it by 9 it equals 90 and if you take 1 oz of oil and times it by 9 it equals 9 then take 90+9=99

Subtract

from both sides

Simplify:

Multiply 10 on both sides:

Simplify

So your answer is
x=60. :)
I can't see. This is kinda blurry
That looks confusing can u explain better