Question

1. \\((9r^3 + 5r^2 + 11r) + (-2r^3 + 9r - 8r^2)\\)

\\(7r^3 - 3r^2 + 20r\\)
\\(11r^3 - 4r^2 + 19r\\)
\\(11r^3 + 13r^2 + 2r\\)
\\(7r^3 + 14r^2 + 3r\\)

Explanation:

Step1: Combine like terms for \( r^3 \)

\( 9r^3 + (-2r^3) = (9 - 2)r^3 = 7r^3 \)

Step2: Combine like terms for \( r^2 \)

\( 5r^2 + (-8r^2) = (5 - 8)r^2 = -3r^2 \)

Step3: Combine like terms for \( r \)

\( 11r + 9r = (11 + 9)r = 20r \)

Step4: Combine all terms

\( 7r^3 - 3r^2 + 20r \)

Answer:

A. \( 7r^3 - 3r^2 + 20r \)