Question

1. 8 + 4a + 6.2 - 9a

Explanation:

Step1: Group like terms

$(8 + 6.2) + (4a - 9a)$

Step2: Calculate constant terms

$8 + 6.2 = 14.2$

Step3: Calculate variable terms

$4a - 9a = -5a$

Step4: Combine results

$14.2 - 5a$

Answer:

$14.2 - 5a$