Which expression can be used to find the sum of the polynomials?
(9 - 3x²) + (-8x² + 4x + 5)

Solution:

Let P(x) = (9 - 3x²) and Q(x) = (-8x² + 4x + 5)

Sorting and writing the terms in the standard form of polynomials,

P(x) = -3x² + 9 --- (1)

Q(x) = -8x² + 4x + 5 --- (2)

Let us add the polynomials by grouping the like terms, we have

P(x) + Q(x) = (-3 - 8)x² + 4x + (9 + 5)

P(x) + Q(x)= -11x² + 4x + 14

Which expression can be used to find the sum of the polynomials?
(9 - 3x²) + (-8x² + 4x + 5)

Summary:

The expression P(x) + Q(x) can be used sorting the like terms to find the sum of the polynomials, (9 - 3x²) + (-8x² + 4x + 5) which gives, P(x) + Q(x)= -11x2 + 4x + 14.