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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?
SAT Math 8.3 Algebra and Functions 297 Views
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Description:
SAT Math 8.3 Algebra and Functions
- Algebra and Functions / Systems of Linear Equations and Inequalities
- Product Type / SAT Math
- Algebra / Solve systems of equations
- Algebra / Solve systems of equations
- Algebra / Solve systems of equations
- Algebra / Solve systems of equations
- Heart of Algebra / Systems of linear equations in two variables (word problems)
Transcript
- 00:02
Here’s your shmoop du jour, brought to you by the difference of two squares.
- 00:06
Sure, all squares have their differences…but we hope these two can work things out.
- 00:12
If 9x2 - y2 = 15 and 3x - y = 3, what does 3x + y equal?
- 00:23
The most important thing is to recognize that, in this
- 00:25
problem, 9x squared minus y squared is a difference of two squares…
Full Transcript
- 00:33
…so “a squared minus b squared” can be factored into “a minus b times a plus b”.
- 00:41
9x squared is 3x times 3x.
- 00:43
So we can factor the first equation so it becomes (3x + y) times (3x - y) = 15.
- 00:50
Then we give a little whistle and call over the second equation…which we can now substitute:
- 00:55
(3x + y) times 3 = 15; then, dividing both sides by 3, we get 3x + y = 5.
- 01:01
So our correct answer is 5. Good boy. Now…roll over.
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