The answer is 5 gallons
Its very simple.
Turn 60% and 10% into decimals ( .60 and .10)
Multiply 8 gallons ( brand A ) by .60 and you get 4.8 gallons
Multiply 2 gallons ( brand B ) by .10 and you get .2 gallons
Add them up and you get 5 gallons.
All you have to do is solve for x. See the following steps below.
Step 1. Subtract

from both sides

Step 2. Simplify

to

First find the absolute value of -16.75. |-16.75|= 16.75
Then multiply that by 2. 16.75x2=33.5
So 2|-16.75| simplified is 33.5