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Instructional Video7:38
Curated Video

Can You Solve The Alien Extinction Riddle? Hard Job Interview Question

6th - 11th
A single alien lands on Earth. Every day after that, each alien on Earth undergoes a transformation, which could be any of the four equally likely events: (a) the alien dies, (b) the alien does nothing, (c) the alien replicates itself (2...
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Instructional Video3:03
Khan Academy

Parallel Lines 2

7th - 9th
Can you tell, algebraically, if three lines are parallel? In this video, Sal demonstrates how to rewrite linear equations in slope-intercept form and compare the slope of each line.
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Instructional Video3:48
Khan Academy

Parallel Lines

7th - 9th
Here is fairly basic video that takes three equations, each written in slope-intercept form, with the goal of determining whether the lines are parallel.  Sal graphs each of the equations on the same coordinate plane to show how their...