WEBVTT

1
00:00:00.000 --> 00:00:04.354
Here is the problem: 6x minus 8 less than negative 8.

2
00:00:04.804 --> 00:00:08.461
Solve the inequality and give the answer in interval notation.

3
00:00:09.261 --> 00:00:16.215
Move everything to one side and isolate the variable. Collect terms: 6x less than 0.

4
00:00:16.665 --> 00:00:32.838
Test one point in each interval (sign chart). (-∞, 0): test x equals negative 1 → sign minus → included; (0, ∞): test x equals 1 → sign plus → excluded.

5
00:00:33.288 --> 00:00:36.341
Decide the endpoints. 0: excluded.

6
00:00:36.791 --> 00:00:38.300
Write the solution set.

7
00:00:39.100 --> 00:00:41.468
So the answer is (-∞, 0).

8
00:00:41.918 --> 00:00:57.092
The inequality holds exactly for x in (-∞, 0). Points where the expression is undefined are never included, and endpoints are included only for less than or equal to or greater than or equal to where the expression equals zero.

9
00:00:57.892 --> 00:01:01.770
x equals negative 1: satisfies the inequality.

10
00:01:02.220 --> 00:01:05.808
x equals 1: does not satisfy the inequality.
