SAT Math 3.4 Algebra and Functions

SAT Math 3.4 Algebra and Functions

FunctionsEquations and Graphs of Linear
Linear Functions
Heart of AlgebraLinear functions in two variables (word problems)
LanguageEnglish Language
Product TypeSAT Math
SAT MathAlgebra and Functions
Systems of EquationsGraphing
Linear Equations

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).