Answer:
Step-by-step explanation:
Given that,
y = x + 6 equation 1
3x - 3y = -18. Equation 2
Substitute equation 1 into equation 2
3x-3(x+6) = -18
3x - 3x - 18 = -18
-18 = -18
Therefore, it has no solution. Check attachment for echelon matrix solution
B. y = -2x + 5 equation 1
2x + y = -7. Equation 2
Substitute equation 1 into 2
2x -2x + 5 = -7
5 = -7
Since the equation is not balance, then, it has infinite numbers of solution.
C. y = -4x + 11. Equation 1
6x + y = 11. Equation 2
Substitute equation 1 into 2
6x - 4x + 11 = 11
2x = 11 - 11
2x = 0
x = 0
Also, y = -4x + 11
y = 0 + 11 = 11
Then, this has a unique solution I.e. one solution.