WEBVTT

1
00:00:00.000 --> 00:00:04.098
Here is the problem: 8x minus 9 equals 16.

2
00:00:04.548 --> 00:00:09.180
A linear equation in x: isolate x using inverse operations.

3
00:00:09.980 --> 00:00:11.513
Start with the equation.

4
00:00:11.962 --> 00:00:13.715
Add 9 to both sides.

5
00:00:14.165 --> 00:00:16.104
Divide both sides by 8.

6
00:00:16.904 --> 00:00:22.291
So the answer is x equals 25 over 8 approximately 3.125.

7
00:00:22.741 --> 00:00:32.203
Doing the same operation to both sides keeps the equation balanced. Undoing addition, then multiplication, leaves x alone.

8
00:00:33.003 --> 00:00:41.525
x equals 3.125: left side equals 16, right side equals 16, which checks out.