9b^2-(-4b)^2
is this 9b^2+4b^2 or 9b^2+16b^2?
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
Oops. I believe you are correct. Sorry about that. The parentheses led me astray.
i think it is 25b^2 I am not sure
To simplify the expression 9b^2 - (-4b)^2, let's break down the steps.
First, we need to evaluate the term (-4b)^2. To do this, we square the value inside the parentheses, which is -4b. Squaring a negative number eliminates the negative sign, so (-4b)^2 becomes (4b)^2.
Next, we can square the term (4b)^2. Squaring a term with both a coefficient and a variable involves squaring each separately. The coefficient 4 squared is 16, and the variable b squared is b^2. So, (4b)^2 becomes 16b^2.
Now, we substitute the simplified term (16b^2) back into the original expression: 9b^2 - (-4b)^2. It becomes 9b^2 - 16b^2.
Therefore, the expression simplifies to 9b^2 - 16b^2.