Answer:
10 is the answer hope this helps :)
I don’t see the table necessary in order to solve this question
Y=6x+4
Blanks from left to right:
-14,-2,10,22,6x+4
So, how much acid is there in 6 gallons? well is 20% acid or (20/100), so the amount of acid in it just (20/100) * 6 or 1.2, the rest is say water.
now, if we want a 90% solution, and say we add "y" gallons, how much acid is in it? well (90/100) * y, or 0.9y.
now let's add "x" gallons of pure acid, now, pure acid is just pure acid, so is 100% acid, how much acid is there in it? (100/100) * x, or 1x or just x.
we know whatever "x" and "y" amounts are, they -> x + 6 = y
and we also know that x + 1.2 = 0.9y
58=7/4x
Multiply both sides by 4 so the fraction cancels out:
232=7x
Divide both sides by 7:
x=33.14 (rounded)
Hope this helps :)