WEBVTT

1
00:00:00.000 --> 00:00:04.319
Here is the problem: 2x minus 5 equals negative 5.

2
00:00:04.769 --> 00:00:09.529
A linear equation in x: isolate x using inverse operations.

3
00:00:10.329 --> 00:00:11.873
Start with the equation.

4
00:00:12.323 --> 00:00:14.088
Add 5 to both sides.

5
00:00:14.538 --> 00:00:16.535
Divide both sides by 2.

6
00:00:17.335 --> 00:00:20.911
Now look at the graph of the left side minus the right side.

7
00:00:21.361 --> 00:00:25.076
It crosses zero exactly at the solutions we found.

8
00:00:25.876 --> 00:00:28.094
So the answer is x equals 0.

9
00:00:28.543 --> 00:00:37.761
Doing the same operation to both sides keeps the equation balanced. Undoing addition, then multiplication, leaves x alone.

10
00:00:38.561 --> 00:00:45.852
x equals 0: left side equals negative 5, right side equals negative 5, which checks out.