Question

1. $2r^3 + r^2$ (if $r = 6$)

Explanation:

Step1: Combine like terms

$2r^2 + r^2 = 3r^2$

Step2: Substitute $r=6$

$3\times(6)^2 = 3\times36$

Step3: Calculate final value

$3\times36 = 108$

Answer:

108