Question

9.
1.5r - 3r + 8r + 2.5r

Explanation:

Step1: Group like terms

$(1.5r - 3r + 8r + 2.5r)$

Step2: Combine coefficients

$(1.5 - 3 + 8 + 2.5)r$

Step3: Calculate coefficient sum

$9r$

Answer:

$9r$