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ACT Math Intermediate Algebra Drill 1, Problem 3. Can you find the value of a in this expression?
SAT Math 5.1 Algebra and Functions 198 Views
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Description:
SAT Math 5.1 Algebra and Functions
Transcript
- 00:02
And here's your shmoop du jour...
- 00:04
If 3x squared - 6 = 18, what does x squared - 2 equal?
- 00:10
And here are the possible answers...
- 00:14
Ok, so the key to this problem is figuring out how 3x squared - 6 = 18 relates
- 00:21
to x squared - 2.
Full Transcript
- 00:24
And no, he's not her second cousin.
- 00:27
First, we see that both have an x squared in their equations...
- 00:31
so let's try solving for that.
- 00:33
Start with the first equation..
- 00:35
Add 6 to both sides... so 3x squared = 24.
- 00:40
Divide both sides by 3, and we have that x squared = 8.
- 00:45
Now, we can plug x squared = 8 into the second equation:
- 00:49
x squared - 2 = 8 - 2...which equals 6.
- 00:54
The answer is A.
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