ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
Pre-Algebra Videos 36 videos
ACT Math: Elementary Algebra Drill 5, Problem 4. How old is Thalia?
ACT Math: Pre-Algebra Drill 1.2. What proportion of Jenna's day is spent Wii-swimming?
ACT Math 2.2 Pre-Algebra 421 Views
Share It!
Description:
ACT Math Pre-Algebra: Drill 2, Problem 2. Solve for y.
Transcript
- 00:03
Here's a question you can really shmoop to...
- 00:07
Solve for y: 100 over y minus 16 equals 40. And here are the potential answers...
- 00:16
OK, what's this fine problem asking us to do?
- 00:18
Eh. It's a pretty vanilla test to see if we can handle a variable in the denominator.
- 00:24
So... first things first -- let's simplify a bit and add 16 to both sides... to get 100
Full Transcript
- 00:30
over y equals 56.
- 00:33
Now let's get that twisted denominator y on top as a numerator, and multiply both sides
- 00:38
by y... to get 100y over y equals 56y.
- 00:43
Why? Because we said so.
- 00:45
So that's 100y on the left and 56y on the right
- 00:48
Divide both sides by 56 and we have y equals 100 over 56.
- 00:53
Now time to reduce. Thank you, Curves.
- 00:56
Both numbers are even, so we know we can divide by 2... which gives us 50 over 28.
- 01:01
Whoops... still even. So divide by 2 again and we have 25 over 14.
- 01:05
Boom. The answer is D.
- 01:07
As in, "Dangerous denominators."
Related Videos
ACT Math: Plane Geometry Drill 3, Problem 1. What is the area of the trapezoid shape in the video?
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.
It's impressive that these expressions are able to stay so rational even when they're having operations performed on them.
Jack and Jill went up the hill to fetch a pail of water. But what happened when they got up there? They’ve been gone an awfully long time…