If P = –(x – 2), Q = –2(y +1) and R = –x + 2y, find a, when P + Q + R = ax.

Find the values of following polynomials at m = 1, n = –1 and p = 2:

(a) m + n + p

(b) m² + n² + p²

(c) m³ + n³ + p³

(d) mn + np + pm

(e) m³ + n³ + p³ – 3mnp

(f) m²n² + n²p² + p²m²

If A = 3x² – 4x + 1, B = 5x² + 3x – 8 and C = 4x² – 7x + 3, then find:

(i) (A + B) – C

(ii) B + C – A

(iii) A + B + C

From the sum of x² – y² – 1, y² – x² – 1 and 1 – x² – y² subtract – (1 + y²).

Subtract the sum of 12ab –10b² –18a² and 9ab + 12b² + 14a² from the sum of ab + 2b² and 3b² – a².