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Math II Videos 98 videos
This video covers both independent and dependent events, although we much prefer independent events. Dependent events are just so dang clingy.
Disjoint events are events that cannot happen at the same time. If one happens, the other doesn't. Simple as that. Overlapping events, on the other...
SAT Math 1.1 Numbers and Operations. How many combinations of beverage and cereal can be made?
Elementary Algebra: Solve for x 349 Views
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Description:
ACT Math Section: Elementary Algebra Drill 3, Problem 3. Solve for x.
- Elementary Algebra / Solving simple quadratic equations
- Product Type / ACT Math
- Foreign Language / Arabic Subtitled
- Foreign Language / Korean Subtitled
- Foreign Language / Chinese Subtitled
- Foreign Language / Spanish Subtitled
- Algebra / Solve equations and inequalities in one variable
- Algebra / Solve equations and inequalities in one variable
- Algebra / Use polynomial identities to solve problem
- Algebra / Solve equations and inequalities in one variable
- Algebra / Solve equations and inequalities in one variable
- Algebra / Use polynomial identities to solve problems
- Elementary Algebra / Solve quadratic equations by factoring
Transcript
- 00:03
And here is your shmoop de jour.
- 00:05
Solve for x: x squared plus 6x plus 8 equals 0
- 00:09
And here are the potential answers...
- 00:16
OK. Any time we see equations in this format -- where there's an x squared then and
- 00:21
x then an integer -- odds are high that they're asking us to factor.
Full Transcript
- 00:25
What 2 numbers can be multiplied to get 8... and can also be added to get 6?
- 00:31
Well, the factors of 8 are 1 and 8; that won't work...
- 00:38
...what about 2 and 4? Ding ding ding!
- 00:40
So... 2 times 4 is 8... and 2 PLUS 4 is 6... so we can just rewrite the factored version as
- 00:49
The quantity x plus 2 times the quantity x plus 4... equals zero.
- 00:54
Now if either of these guys is 0, the whole equation is zero because zero times anything...
- 00:59
is zero. Yeah, it brings everyone else down to its level.
- 01:00
So if x is negative 2, this part is 0... and if x is negative 4, this part is 0.
- 01:06
x has to be one of those answers... and OUR answer here is either A or B... which is...
- 01:11
option D. Done
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