The problem presented in the text is in regards to graphing ordered pairs. An equation to express the relationship between the pair is given as;

y = 4 - x

^{2}

The solution requested is a graph x and y for all pairs where x is an integer from -3 to 3.

For x = -3, the author of the book substituted in this manner;

y = 4 - (-3)

^{2}

My question is; why would the substitution not be in this form; y = 4 - (-3

^{2})?

The two methods generate different values for x

^{2}. The first generates 9, and the second generates -9.

So, again, why one way and not the other?