Question

All of the following expressions are equivalent, except ______.

x - 7
7 + (-x)
-x + 7
7 - x

Answer 1

x - 7

Explanation:

Answer 2

x - 7

Explanation:

Let's let x = 4 and see which one would be different

x - 7 = 4 - 7 = -3

7 + (-x) = 7 + -4 = 3

-x + 7 = -4 + 7 = 3

7 - x = 7 - 4 =3

As you can see, the top answer would be negative while all the rest are positive. This is because, in that case, the negative sign was attached to the 7 instead of the x.