Let x gallons be the amount of pure antifreeze that should be added to the 30% solution to produce a solution that is 65% antifreeze. Then the total amount of antifreeze solution will be x+3 gallons.
There are 30% of pure antifreeze in 3 gallons of solution, then
3 gallons - 100%,
a gallons - 30%,
where a gallons is the amount of pure antifreeze in given solution.
Mathematically,

Now in new solution there will be x+0.9 gallons of pure antefreeze.
x+3 gallons - 100%,
x+0.9 - 65%
or

Answer: he should add 3 gallons of pure antifreeze.
Answer:
D: y=6x
Step-by-step explanation:
y=mx+b
b=0
y=mx
-3=m * (-1/2)
m=6
y=6x
3.24 + 5.70 + 6.17 = 15.11
20.00 - 15.11 = 5.11
He got 5.11$ of change back.
Answer:
z=514
Step-by-step explanation:
120=z-394
+394. +394
514=z
Hope this helps