SAT Math 5.3 Algebra and Functions

SAT Math 5.3 Algebra and Functions

AlgebraFactoring
Functions
Elementary Number TheoryFactors, Multiples, and Remainders
Heart of AlgebraSystems of linear equations in two variables (word problems)
MathAlgebra
Polynomials and Rational ExpressionsRemainder Theorem
Product TypeSAT Math
SAT MathAlgebra and Functions

Transcript

00:22

All right, so we’ve got some mystery number, and we know the remainder is 1 when you divide it by 11.

00:29

Now we want to tack on 10 more and do the same… and we need to determine the new remainder.

00:33

We need a quotient… we’ll call that k.

00:36

Let’s work in reverse. But be safe – check the rear view mirror first.

00:41

Multiplying both sides by 11 and then adding back the remainder gives us n = 11k + 1.

00:49

So now we’re looking for the remainder when n + 10 is divided by 11.

00:53

Adding 10 to both sides, n + 10 = 11k + 11.

00:58

Factoring out the 11, so n + 10 = 11(k + 1).

01:06

We want to figure out what the remainder is of (n + 10) divided by 11...

01:11

…so dividing both sides of the equation by 11 makes the left side exactly what we’re

01:14

looking for. When n + 10 is divided by 11 the quotient

01:18

is k + 1 and the remainder is 0. Looks like out answer is (A).

01:22

As in, “Auto repair.”