# How do you solve 9a - 8= 73?

Apr 6, 2018

$a = 9$

#### Explanation:

We just need to solve the equation for $a$

$9 a - 8 = 73$

Add 8 to both sides:

$9 a - 8 + 8 = 73 + 8$

$9 a = 81$

Divide both sides by 9:

$\frac{9 a}{9} = \frac{81}{9}$

$a = 9$

Apr 6, 2018

Solution: $a = 9$

#### Explanation:

Equations should be viewed as logical statements. The equation you give is literally saying that the value of $9 a - 8$ is exactly equal to the value of $73$.

From this, it follows that we are allowed to make certain manipulations. For example, we can add numbers to both sides of the equation. Doing such yields:

$9 a - 8 = 73$,
$9 a - 8 \left(+ 8\right) = 73 \left(+ 8\right)$, (we add $8$ to both sides)
$9 a = 81$.

We can also divide both sides of the equation by some number, as long as it's the same number. We will divide by $9$.

$9 a = 81$,
$\frac{9 a}{9} = \frac{81}{9}$, (we divide both sides by $9$)
$a = 9$.

So our answer is $a = 9$.