Answer:
The answer is B.
Step-by-step explanation:
To Find :
How many gallons of a 80% antifreeze solution must be mixed with 100 gallons of 20% antifreeze to get a mixture that is 70% antifreeze.
Solution :
Let, x gallons of 80% antifreeze solution is required :
So,

Therefore, 500 gallons of 80% antifreeze solution is required.
Here are the log properties you need:
Okay so, we switch out f(x) with y - I’m sure you know this and we get y=2+3x/x-2.
Now just interchange x and y -> x=2+3y/y-2, now multiply both sides with (y-2), we get (y-2)x=2+3y.
Multiply x with the brackets, getting xy-2x=2+3y. Move 3y to the left changing it’s sign, also for -2x to the right: xy-3y=2+2x.
Factor out y from (xy-3y) and get (3-x)y=2+2x - now divide both sides by (3-x) resulting in y=2+2x/3-x .