Question

simplify the following expression.
$6a + (3b^2 - 1) + 2ab - (9b^2 - 3ab + 7a)$
a. $-6b^2 + 5ab - a - 1$
b. $-6b^2 - ab + 13a - 1$
c. $-6b^2 + 5ab + 13a + 1$
d. $-6b^2 - ab - a + 1$

Explanation:

Step1: Remove parentheses

$6a + 3b^2 - 1 + 2ab - 9b^2 + 3ab - 7a$

Step2: Group like terms

$(3b^2 - 9b^2) + (2ab + 3ab) + (6a - 7a) - 1$

Step3: Combine like terms

$-6b^2 + 5ab - a - 1$

Answer:

A. $-6b^2 + 5ab - a - 1$