Okay... so I'm a little bit confused.
2x^2 + 3xy^2 - 4y^2
= 2 (2^2)+3 (2) (-4) - 4 (-4^2)
= 2 (4) + (-24) - 64
= 8 - 24 - 64
= - 80
I know the right answer is -80 but what I don't get is why is it negative? Can anyone explain it to me? When I first solve them I answered positive 80 but then I found out it’s wrong.. So anyone please explain why is it negative 80. Thanks in advance!
2x^2 + 3xy^2 - 4y^2
= 2 (2^2)+3 (2) (-4) - 4 (-4^2)
= 2 (4) + (-24) - 64
= 8 - 24 - 64
= - 80
I know the right answer is -80 but what I don't get is why is it negative? Can anyone explain it to me? When I first solve them I answered positive 80 but then I found out it’s wrong.. So anyone please explain why is it negative 80. Thanks in advance!