9b^2-(-4b)^2
is this 9b^2+4b^2 or 9b^2+16b^2?
4 answers
9b^2 + 16b^2
Actually, DrBob22, I disagree.
neither
The second choice is almost correct. It is missing a minus sign. It should be: 9b^2-16b^2
Why?
(-4)^2 (b)^2 => 16b^2
remember, you're square both the coefficient and the variable.
note: the minus sign is not in the parenthesis, so you do not do anything to it.
Therefore, you have 9b^2-16b^2
neither
The second choice is almost correct. It is missing a minus sign. It should be: 9b^2-16b^2
Why?
(-4)^2 (b)^2 => 16b^2
remember, you're square both the coefficient and the variable.
note: the minus sign is not in the parenthesis, so you do not do anything to it.
Therefore, you have 9b^2-16b^2
Oops. I believe you are correct. Sorry about that. The parentheses led me astray.
i think it is 25b^2 I am not sure