ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
Algebra and Functions Videos 140 videos
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...
SAT Math 3.4 Algebra and Functions 239 Views
Share It!
Description:
SAT Math 3.4 Algebra and Functions
Transcript
- 00:02
Put this in your calculator and shmoop it...
- 00:05
2 xy + 2 = 1 over x + y.
- 00:09
Solve for y in terms of x.
- 00:11
And here are the potential answers...
- 00:18
It's important to remember that when a question asks us to solve for something in terms of
Full Transcript
- 00:21
something else, it's just asking us to isolate the variable.
- 00:27
So let's get started. We need to isolate y.
- 00:30
We can do this by putting all the terms with y's on one side first.
- 00:34
We subtract y from both sides, and 2 from both sides.
- 00:38
Next, we'll factor out the y on the left side of the equation, and we're left with y times
- 00:42
the quantity 2x - 1 is equal to 1/x - 2.
- 00:47
Then, we divide both sides by 2x - 1, so our y is isolated.
- 00:52
We can factor out 1/x from the top half of the right side,
- 00:56
and we'll be left with (1/x)(1 - 2x) on top.
- 01:02
Now, the top has 1 - 2x, and the bottom has 2x - 1.
- 01:06
Well look at them closely...they're just negatives of each other.
- 01:09
So, we can rewrite the bottom as -1 times 1 - 2x
- 01:15
We can clearly see that 1 - 2x can be cancelled out.
- 01:18
We're left with y = -1/x.
- 01:23
So our answer is (A).
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...