Question

How do you evaluate `68 - y^2` for y = 5?

Answer 1

Replace `y` with `5` in the expression and perform the arithmetic to get
`color(white)("XXXX")` `43`

Explanation:

`68-y^2` with `y=5`
becomes
`68 -5^2`
`color(white)("XXXX")` `=68 - 25`
`color(white)("XXXX")` `= 43`