How do you solve 9a - 8= 73?

2 Answers
Apr 6, 2018

a=9

Explanation:

We just need to solve the equation for a

9a-8=73

Add 8 to both sides:

9a-8+8=73+8

9a=81

Divide both sides by 9:

(9a)/9=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 9a - 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:

9a - 8 = 73,
9a - 8 (+ 8) = 73 (+ 8), (we add 8 to both sides)
9a = 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.

9a = 81,
(9a)/9 = 81/9, (we divide both sides by 9)
a = 9.

So our answer is a = 9.