I would appreciate any help I can get for this question.
How much pure acid should be mixed with 2 gallons of a 40% solution in order to get a 70% acid solution?

Let x=the amount of pure acid.

We add that to the 2 gallons of 40% and get:

.40(2)+x

This must equal a 70% solution which will be 2 gallons plus the x amount.

.70(2+x)


.40(2)+x=.70(2+x)

Solve for x.

I would appreciate any help.
Number your paper from 0 to 25. Using the difference [remember: difference means to subtract] of two squares, the difference of two cubes, or the difference of a square and a cube; find all the values from 0 to 25. Use 1 as the base very sparingly (no more than twice).
example=3(cubed) minus 4 (squared)=27-16

What are some examples of a binomial?