ShmoopTube

Where Monty Python meets your 10th grade teacher.

Search Thousands of Shmoop Videos


Math Videos 320 videos

SAT Math 1.3 Numbers and Operations
190 Views

SAT Math 1.3 Numbers and Operations. x and y must be which of the following?

SAT Math 2.4 Numbers and Operations
384 Views

SAT Math 2.4 Numbers and Operations

See All

SAT Math 2.2 Algebra and Functions 298 Views


Share It!


Description:

SAT Math 2.2 Algebra and Functions. What value of y is correct?

Language:
English Language

Transcript

00:02

Put this in your calculator and shmoop it...

00:05

If x to the y power... to the y power... to the y power...

00:10

to the y power... equals x to the 81st power... then y can be which of the following?

00:17

And here are the potential answers...

00:23

There may be a lot of parentheses here, but don't panic.

00:25

All we need is a simple exponent rule. Remember this rule?

00:31

When we take an exponent to an exponent, all we have to do is multiply the two exponents together.

00:38

So x to the y to the y is the same thing as x to the y squared.

00:44

So x to the y squared to the y to the y is the same thing as x to the y to the fourth power.

00:53

The base of both sides are the same, so the exponents of both sides must be the same.

01:00

Yeah, probably.

01:01

So y to the fourth is equal to 81.

01:03

What number, to the fourth power, is 81?

01:06

Well, 3 times 3 is 9 times 3 is 27 times 3 is 81, but

01:10

3 isn't the only number that's equals 81 when raised

01:14

to the fourth power. What's another one that works?

01:18

Negative 3 to the fourth power is also 81.

01:21

The negative cancels out since the exponent is even.

01:25

So yep, E is our answer.

Related Videos

SAT Math 9.4 Algebra and Functions
1300 Views

SAT Math 9.4 Algebra and Functions

SAT Math 9.2 Algebra and Functions
377 Views

SAT Math 9.2 Algebra and Functions

SAT Math 2.1 Geometry and Measurement
2779 Views

SAT Math 2.1 Geometry and Measurement. What is the measure of angle z in terms of x and y?

SAT Math: Identifying an Equation for the Average of Two Percentages
23 Views

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: Which Equation Represents Profit?
13 Views

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...