Question

-3² = -1*3² = -1 * 9 = -9 (order of operations) while (-3)² = (-3)(-3) = +9 or 9

Evaluate: Z2 – X2 -XY if X = -2, Y = 3, and Z = -4 (please see section 1.8 for further review)

Answer 1

For the given values
`Z^2  - X^2 - XY  = 18`

Explanation:

Here, the given values are:

X = -2, Y = 3 and Z = -4

To find the value of the expression:
`Z^2  - X^2 - XY`

Now, substitute the given values in the expression, we get

`Z^2  - X^2 - XY  = (-4)^2  - (-2)^2  - (-2)(3)\\=16 - 4 + 6\\=12 + 6 = 18`

or,
`Z^2  - X^2 - XY  = 18`

Hence, for the given values the simplified value is 18.