Px - 45 = QX + 75
Px - Qx = 75 + 45 = 120
A. If P = - 45 and Q = - 75, then
- 45x + 75 x = 120
30x = 120 and x = 40
B. If P = 45 and Q = - 15, then
45x - 15x = 120
30x = 120
x = 40
D. If P = 15 and Q = 75, then
15x - 75x = 120
- 60x = 120
x = - 2
C. If P = 15 and Q = 15, then
15x - 15x = 120
0 = 120 which is absurd.
Hence, P = 15 and Q = 15 result in an equation with no solution.