SOLUTION: Okay, I have this problem I got wrong on my test but I thought I got it right. Evaluate the expression below if x=-1 and y=3

Algebra ->  Expressions -> SOLUTION: Okay, I have this problem I got wrong on my test but I thought I got it right. Evaluate the expression below if x=-1 and y=3       Log On


   

Question 901534: Okay, I have this problem I got wrong on my test but I thought I got it right.

Evaluate the expression below if x=-1 and y=3
3x^2-y^2
I got -12, but my teacher check it as wrong so I went to the online calculator it also said -12. I am confused please help.
cmur9133
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Evaluate 3x%5E2-y%5E2 for x=-1 and y=3.

Substitute assigned values:
3%28-1%29%5E2-%283%29%5E2

Compute the expression:
3%2A1-9
3-9
highlight%28-6%29