ACT Math 1.3 Pre-Algebra

ACT Math Pre-Algebra Drill 1, Problem 3. Can you find the product of two square roots?

ACT MathPre-Algebra
ACT MathematicsPre-Algebra
AlgebraSquare Roots
Foreign LanguageArabic Subtitled
Chinese Subtitled
Korean Subtitled
Spanish Subtitled
LanguageEnglish Language
Pre-AlgebraSquare roots and approximations
Square roots of numbers
Product TypeACT Math

Transcript

00:19

We'll rarely be asked to calculate a square root that doesn't come out even on a test like this...

00:24

...so if we feel like we've been backed into that corner of actually having to calculate it...

00:28

...we may have messed up somewhere upstream.

00:30

That's not to say they won't ever throw a weird one in there,

00:33

but... it's just something to keep in mind.

00:35

So, in this case we have to think about the factors

00:37

of 32... 2 and 16 and 4 and 8.

00:42

First we have the square root of 32. What perfect squares go into 32 evenly?

00:47

Well, 4 does... but the bigger the better, in this case anyway...

00:51

16 times 2 equals 32, and 16 is 4 squared.

00:55

So we can rewrite this as the square root of 16 times 2, then we can pull out a 4 to

01:00

make it 4 square root of 2.

01:03

Next on the docket is the square root of 8. Now 4 is the best we can do.

01:07

The square root of 4 times 2 can be rewritten as 2 square root of 2.

01:12

When we multiply these two together, we get 4 times 2 is 8...

01:17

...and then square root of 2 times square root of 2 is... 2.

01:22

Multiply those two numbers together, and we're left with 16...

01:25

So the answer C.

01:25

As in, "Calculating villains."