Question

1. 10r - 5r + 3r - 8r

Explanation:

Step1: Combine like terms (10r-5r)

$10r - 5r = 5r$

Step2: Add the next like term (+3r)

$5r + 3r = 8r$

Step3: Subtract the final like term (-6r)

$8r - 6r = 2r$

Answer:

$2r$