Question

1. solve each system by substitution. 7x+4y=-21
3x+y=-4

2.
-8x+7y=-6
y=6

Answer 1

1. y = -4 - 3x
7x + 4(-4 - 3x) = -21
7x - 16 - 12x = -21
-5x = -5
x = 1
y = -4 - 3= -7

2. y = 6
-8x + 42 = -6
48 = 8x
x = 6