00:02
If we're given the inequality, 5x minus 12 is greater than zero, and we're given some solutions, and we want to verify whether or not the solutions are correct.
00:13
We can use substitution to do that.
00:16
So this first one, we're given x equals three.
00:21
This one here, we're given x equals negative three.
00:25
This one, we're given x equals five halves.
00:29
And over here, we're given x equals three halves.
00:31
So we have these four solutions, and we're going to determine whether each value of x, is actually a solution to the inequality, 5x minus 12 is greater than 0.
00:43
So on this one, x equals 3, 5 times 3 minus 12 is greater than 0.
00:49
5 times 3 is 15 minus 12 is greater than 0.
00:55
And we get 3 is greater than 0.
00:57
3 is in fact greater than 0.
00:59
So x equals 3 is a solution to this inequality.
01:04
Our second choice, negative 3, 5 times 0 ,000.
01:07
Negative 3 minus 12 is greater than 0.
01:11
5 times negative 3 is negative 15 minus 12 is greater than 0.
01:16
And we get negative 27 is greater than 0.
01:19
Negative 27 is not greater than 0.
01:22
This is not a true statement.
01:23
So x equals negative 3 is not a solution to this inequality...