Answer
$$a = 2A - b$$
Work Step by Step
To solve this equation for $a$, we need to isolate $a$.
We first divide both sides by $\frac{1}{2}$, which means we will multiply each side by the inverse, which is $2$:
$$2A = a + b$$
We then subtract $b$ from each side:
$$a = 2A - b$$
