Question

The sum of 4x^2 - 3x + 2, -x^2 + 5x - 7 and 2x^2 - x + 1 is

Assertion (A): 3xy and -5yx are like terms. Reason (R): Like terms have the same algebraic factors.

From the sum of 3a^2 - 4ab + b^2 and 2a^2 + 6ab - 3b^2, subtract 4a^2 - ab - 5b^2. Find the value of the result when a = 2 and b = -1.