2x + 5y = -3 ⇒ 2x + 5y = -3
1x + 8y = 4 ⇒ <u>2x + 16y = 8
</u> -<u>11y</u> = <u>-11 </u>
-11 -11
y = 1
2x + 5(1) = -3
2x + 5 = -3
<u> -5 -5</u>
<u>2x</u> = <u>-8</u>
2 2
x = -4
(x, y) = (-4, 1)
2x + 1y = 7 ⇒ 2x + 1y = 7
1x - 2y = -14 ⇒ <u>2x - 4y = -28</u>
<u>5y</u> = <u>35</u>
5 5
y = 7
2x + 7 = 7
<u> -7 -7</u>
<u>2x</u> = <u>0</u>
2 2
x = 0
(x, y) = (0, 7)

Use the formula above to find the surface area of a cylinder.
For the given cylinder the given data is the height (6mi) and diameter (16mi), use the diameter to find the radius:

Surface area:

Then, the surface area of the given cylinder is: 224π square miles
The answer is D because the shaded area must go to the origin and it must have a non-dashed line because having 5 sundaes and 10 cones is possible.
Red: y= 2x
Black: y= 2x
Yellow: y= -3x
Green: zero slope
Blue: undefined slope
What's the question though?