Part A
1, - 2x + 3y = - 13
3x - 3y = 12
We would apply the method of elimination. Since the coefficients of y in both equations are the same, we would eliminate y by adding both equations. It becomes
- 2x + 3x + 3y + - 3y = - 13 + 12
- 2x + 3x + 3y - 3y = - 1
x + 0 = - 1
x = - 1
We would substitute x = - 1 into the first equation. It becomes
- 2(-1) + 3y = - 13
2 + 3y = - 13
3y = - 13 - 2
3y = - 15
y = - 15/3
y = - 5
The solutions are (- 1, - 5)
2. - 9x - y = 29
9x + y = - 29
We would apply the method of elimination. Since the coefficients of y in both equations are the same, we would eliminate y by adding both equations. It becomes
- 9x + 9x - y + y = 29 + - 29
- 9x + 9x - y + y = 29 - 29
0 - 0 = 0
0 = 0
Infinite number of solutions