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ACT Math Videos 164 videos
ACT Math: Trigonometry Drill 1, Problem 1. What is the length of y?
ACT Math: Coordinate Geometry Drill 1, Problem 2. Solve the inequality and determine which solution is shown on the number line.
ACT Math 4.2 Elementary Algebra 301 Views
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Description:
ACT Math Elementary Algebra Drill 4, Problem 2. Solve for x.
Transcript
- 00:02
Time for your daily dose of Shmoop. This won't hurt a bit.
- 00:06
Solve for x: the absolute value of x plus 1 all over 2... is less than 3.
- 00:12
And here are the potential answers...
- 00:19
It's yet another absolutely fabulous... absolute value question.
- 00:22
Let's start by ignoring the absolute value lines and solve as if they were all positive numbers.
Full Transcript
- 00:28
We multiply both sides by 2 to get x plus 1 is less than 6.
- 00:32
Subtract 1 from both sides and we have x is less than 5, so our potential answers are
- 00:36
only B and C.
- 00:38
Now let's figure out what this problem would be if x were the most negative it could be.
- 00:43
What would make things under the absolute value lines to equal NEGATIVE 3?
- 00:47
We'd have x plus 1 over 2 is less than negative 3, but with no absolute value lines now.
- 00:53
We multiply both sides by 2 and we have x plus 1 is less than negative 6.
- 00:57
Then subtract 1 from both sides and we have x is less than negative 7.
- 01:01
So we have a positive 5 and a negative 7 as the range here.
- 01:05
Which is... this range... and our answer is C.
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