It will not execute the string. You must write the code to do the math.

You have this:

x = 2 <-- integer

"y = 2 * x + 1" <-- string

But you must also have code to solve the problem. An advanced calculator may be what you need. I used a TI-85 in high school and college. That would be easier than writing the code to extract the variables from the string and then performing the math to solve for x.

...later