Answer:
Kilometers most likely for any other measurement would be to small to do so otherwise.
<span>The surface area of a sphere is equal to [4 x Pi x R^2]. In other words, four multiplied by 3.14 multiplied by the radius squared. If the radius of a sphere is 15 yards, the approximate surface area is [4 x 3.14 x (15x15)] = [12.5 x 225] = [2,812 yd^2]. The surface area of a sphere with radius 15 yd is approximately 2,800 yards.</span>
1: Solve for either x or y in one of the equations. So x + y = -1 is y = -x -1
2: substitute the new equation in the opposite equation. So x - (-x - 1) = 7
3: distribute the negative. X + x + 1 = 7
4: combine like terms. 2x + 1 = 7
5: solve for x. Subtract 1 on both sides. 2x = 6
6: divide by 2 to get x by itself. X = 3
7: plug the new value of x into one of the ORIGINAL equations. 3 + y = -1
8: solve for y. Subtract 3 on both sides.
Y = -4
9: the solution is written as (x,y) so the solution would be (3, -4)