32 divided by 2.39 = about 13.3
He can buy 11 peanuts, taking in consideration the .38 cents is WITH tax already included. There is no way to find out the tax rate without the original and the change in the problem other wise.
Simplifying
(x + -16) * 2 = 256
Reorder the terms:
(-16 + x) * 2 = 256
Reorder the terms for easier multiplication:
2(-16 + x) = 256
(-16 * 2 + x * 2) = 256
(-32 + 2x) = 256
Solving
-32 + 2x = 256
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '32' to each side of the equation.
-32 + 32 + 2x = 256 + 32
Combine like terms: -32 + 32 = 0
0 + 2x = 256 + 32
2x = 256 + 32
Combine like terms: 256 + 32 = 288
2x = 288
Divide each side by '2'.
x = 144
Simplifying
x = 144