What do you need to know? give me an equation and i'll help you solve it

<h3>Answer: d. w = -6</h3>
Answer:
<h2>C.</h2>
Step-by-step explanation:
The equationof a circle:

<em>(h, k)</em><em> - center</em>
<em>r</em><em> - radius</em>
<em />
We have <em>center = (4, -1) → h = 4, k = -1</em>, and <em>r = 9</em>.
Substitute:

Answer:
4x^2 +9xy +6y^2
Step-by-step explanation:
Combine like terms. I find it useful to factor out the variable part of the expression so I can see what coefficients are being combined.
7x^2+5xy-3y^2 - (2x^2+3xy-5y^2 + x^2-7xy-4y^2)
= (7 -2 -1)x^2 +(5 -3+7)xy +(-3 +5 +4)y^2
= 4x^2 +9xy +6y^2
Volume for rectangular prism is l x w x h
12cm x 6.5cm x 1.25cm = 97.5cm^3