Both Px + Qy = R and Tx + Uy = V have the same solution (2, 9), meaning the point (2, 9) lies on both lines such that x = 2 and y = 9 makes both equations true.
When you add these equations together, you get
(Px + Qy) + (Tx + Uy) = R + V
→ (P + T ) x + (Q + U ) y = R + V
so the first option is equivalent.
When you subtract the first equation from the second, you get
(Tx + Uy) - (Px + Qy) = V - R
→ (T - P) x + (U - Q) y = V - R
so the third option is also equivalent.
