Oh how I miss the days when math was as simple as 2+2=4.
Educated guess here: By putting parentheses.
Answer: 20
Step-by-step explanation:
Assuming your question is:
Z² - X² - XY X = -2, Y = 3, Z = -4
Substitute values
(-4)² - (-2)² - {(-2)(3)}
{(-4)(-4)} - {(-2)(-2)} - (-6)
(16) - (4) + 6
16 - 4 + 6
20
I did this with a pencil and no calculator while my daughter was practicing her driving. Please let me know if you have trouble reading it. You'll have to add the calculator stuff yourself.