If P = 2x2 – 5x + 2, Q = 5x2 + 6x – 3 and R = 3x2 – x – 1. Find the value of 2P – Q + 3R.
2P – Q + 3R = 2(2x2 – 5x + 2) – (5x2 + 6x – 3) + 3(3x2 – x – 1)
= 4x2 – 10x + 4 – 5x2 – 6x + 3 + 9x2 – 3x – 3
= 4x2 – 5x2 + 9x2 – 10x – 6x – 3x + 4 + 3 – 3
= 8x2 – 19x + 4
Required expression.