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>
The answer should be A. For example, if x = 1, and the ratio between x and y is y is 5 times greater than x, then y would equal 5, which is only true in A.
Or, use the number 5 as an example. If x = 5, and the ratio between x and y is y is 5 times greater than x, then y is 5.
And if you put that into A, y = 5x, it becomes 25 = 5(5)
Then 25 = 25, which is true!
About 14
this is the answer
You can use substitution or elimination or graphing to solve the equation. Since both of the equations are in slope intercept form it will be easier to use substitution or to graph it and find the point of interception.
