Answer and Step-by-step explanation:
Given
ax + by = c
qx + ry = s
(a) the equation has no solutions if a/q = b/r ≠ c/s, when this happens, we say the system of equations has no solution. For example
x + y = 3
x + y = 5
Subtracting first equation from the second we have:
0 = 2 which is impossible.
(b) the equations have infinite solutions if a/q = b/r = c/s, for example
x + y = 2
x + y = 2
Subtracting the first equation from the second we have
0 = 0, since this is always true, then it has infinite solutions.
(c) the equations have unique solutions if a/q ≠ b/r, for example
x + y = 2
x – y = 1
Adding the first and second equation we have
2x = 3, we can get x from here and definitely y, so we have just one solution.