Answer:
im not the best at algebra but
2a+3b+4c
Step-by-step explanation:
subtract
(2a−3b+4c) from the sum of (a+3b−4c),(4a−b+9c) and (−2b+3c−a).
add
=(a+3b−4c)+(4a−b+9c)+(−2b+3c−a)
=(a+4a−a)+(3b−b−2b)+(−4c+9c+3c)
=4a+8c
then subtract
=(4a+8c)−(2a−3b+4c)
=4a+8c−2a+3b−4c
=2a+3b+4c
Collect like terms (x + 7x) + (-1 + 4 - 3)
Simplify
Answer: 8x
The ratio of the radii is 2:1, so the ratio of their surface areas is 4:1. <span>The area of a sphere is defined by 4 * pi * r^2 </span>
<span>So if the radius of the first sphere is 2r, then it would be (2r)^2 = 4r^2 </span>
<span>The rest is the same. So the ratio of their surface areas would be </span>
<span>4 * pi * 4r^2 divided by </span>
<span>4 * pi * r^2 </span>
<span>or 4.</span>
