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ACT Mathematics Videos 164 videos
ACT Math: Coordinate Geometry Drill 1, Problem 1. Which inequality is expressed by the number line?
ACT Math: Intermediate Algebra: Drill 3, Problem 1. Find the fifth number in the series.
ACT Math: Pre-Algebra Drill 1.2. What proportion of Jenna's day is spent Wii-swimming?
ACT Math 3.3 Intermediate Algebra 259 Views
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Description:
ACT Math: Intermediate Algebra Drill 3, Problem 3. Solve the equation for x.
Transcript
- 00:03
Hope you're wearing your smartypants and/or thinking cap for this one.
- 00:07
Solve the following equation for x: y equals three halves x plus 4
- 00:12
4 y equals x plus 1
- 00:14
And here are the potential answers...
- 00:21
OK so what is this question asking?
Full Transcript
- 00:22
It's really just a "substitute n' solve" problem.
- 00:26
In the first equation, y is already isolated, so let's just substitute the first equation
- 00:32
into the second.
- 00:37
4 times the quantity 3 halves x plus 4 equals x plus 1.
- 00:44
Multiplying the 4, we get that 12x over 2... or just 6x... plus 16 equals x plus 1.
- 00:57
We combine like terms...so anything with an x goes together and both constants go together.
- 01:02
5x equals negative 15. Divide 5 from both sides, and we get x equals negative 3.
- 01:08
Looks like our answer is B.
- 01:09
As in, "Bad managing decision."
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