Question

Answer any of the following:

Answer 1

1. Solve the system by substitution -2x+y=-11, 3x-4y=11. 
-2x+y=-11
y = 2x-11

3x-4y=11
3x-4(2x-11)=11
3x -8x + 44 = 11
-5x = -33
x =33/5
y = 11/5

2. Solve the system using elimination- 2x+6y=-12, 5x-5y=10. 
(-2x+6y=-12)5
-10x + 30y = -60

(5x-5y=10)2
10x - 10y = 20

Adding the two equations,
-10x + 30y = -60
10x - 10y = 20

20y = -40
y = -2
x = 0

3. What is the solution of the following system?-3x-2y=-12, 9x+6y=-9. 
-3x-2y=-12
y = -3/2 x + 6

9x+6y=-9
y = -3/2 x - 3/2

Since the slopes are equal then they are parallel lines so they never meet at one point.