Answer:
15) C (3, -4)
16) B (-1, 1)
Explanation:
8x + 6y = 0
8x + 2y = 16
8x + 2y = 16
8x = 16 - 2y
x = 2 - 1/4y
8x + 6y = 0
8(2 - 1/4y) + 6y = 0
16 - 2y + 6y = 0
16 + 4y = 0
4y = -16
y = -4
8x + 2y = 16
8x + 2(-4) = 16
8x - 8 = 16
8x = 24
x = 3
________________
-20x - 3y = 17
10x - 4y = -14
-20x - 3y = 17
-20x = 17 + 3y
x = -17/20 - 3/20y
10x - 4y = -14
10(-17/20 - 3/20y) - 4y = -14
-8.5 - 1.5y - 4y = -14
-8.5 - 5.5y = -14
-5.5y = -5.5
y = 1
-20x - 3y = 17
-20x - 3(1) = 17
-20x - 3 = 17
-20x = 20
x = -1