ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
Algebra Videos 351 videos
We don't like knocking people down to size, but we do like simplifying radicals. Join us?
If fleeing criminals always fled the scene of the crime at perfect right angles, it would be much easier to determine their whereabouts. Fortunatel...
SAT Math 5.7 Numbers and Operations 194 Views
Share It!
Description:
SAT Math 5.7 Numbers and Operations
Transcript
- 00:03
Here’s your shmoop du jour, brought to you by ACDC.
- 00:06
Not a line segment, but some of their songs had good lines…
- 00:14
Points A, B, C, D, and E lie on a straight line. C is the midpoint of AE,
- 00:20
D is the midpoint of CE, and B is the midpoint of AD.
- 00:25
If AB is equal to 6, what is the length of AE?
Full Transcript
- 00:31
Sometimes…it helps if we sketch out the problem…like we’ve done here.
- 00:35
We’re also going to label each segment with what fraction of the AE line it is.
- 00:40
So AC is 1/2 of AE.
- 00:44
CD is 1/4 of AE.
- 00:51
AC + CD makes AD, so AD is 1/2 of AE + 1/4 of AE.
- 00:59
With the addition worked out, AD is 3/4 of AE.
- 01:02
The problem tells us that AB is 6, and AB + AB is AD because B is the midpoint of AD.
- 01:09
This means that the length of AD is 12.
- 01:13
We also know that AD is 3/4 of AE, which allows us to write a short equation.
- 01:17
3/4 times AE = 12. So multiply both sides by the reciprocal of 3/4…or 4/3.
- 01:25
…to get that the length of AE is 16.
- 01:28
And we're done.
Related Videos
SAT Math 2.1 Geometry and Measurement. What is the measure of angle z in terms of x and y?
In 2014, the unemployment rate of one county in California was 7%. In another county, the unemployment rate was 11%. Which of the following express...
Angela is making cookies for a bake sale. She expects each batch of her cookies to sell for $40. It costs her $10 to make one batch of cookies, and...