Squaring / Square Roots / Radicals

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SAT Math › Squaring / Square Roots / Radicals

Questions 1 - 10
1

Simplify the radical expression.

Explanation

Look for perfect cubes within each term. This will allow us to factor out of the radical.

Simplify.

2

According to Heron's Formula, the area of a triangle with side lengths of a, b, and c is given by the following:

Hero

where s is one-half of the triangle's perimeter.

What is the area of a triangle with side lengths of 6, 10, and 12 units?

12√5

4√14

8√14

14√2

48√77

Explanation

We can use Heron's formula to find the area of the triangle. We can let a = 6, b = 10, and c = 12.

In order to find s, we need to find one half of the perimeter. The perimeter is the sum of the lengths of the sides of the triangle.

Perimeter = a + b + c = 6 + 10 + 12 = 28

In order to find s, we must multiply the perimeter by one-half, which would give us (1/2)(28), or 14.

Now that we have a, b, c, and s, we can calculate the area using Heron's formula.

Hero

Hero2

3

Simplify:

Explanation

If you don't already have the pattern memorized, use FOIL. It's best to write out the parentheses twice (as below) to avoid mistakes:

4

has 4 roots, including the complex numbers. Take the product of with each of these roots. Take the sum of these 4 results. Which of the following is equal to this sum?

The correct answer is not listed.

Explanation

This gives us roots of

The product of with each of these gives us:

The sum of these 4 is:

What we notice is that each of the roots has a negative. It thus makes sense that they will all cancel out. Rather than going through all the multiplication, we can instead look at the very beginning setup, which we can simplify using the distributive property:

5

Find the product of (3 + 4i)(4 - 3i) given that i is the square root of negative one.

7 + i

0

12 - 12i

24

24 + 7i

Explanation

Distribute (3 + 4i)(4 - 3i)

3(4) + 3(-3i) + 4i(4) + 4i(-3i)

12 - 9i + 16i -12i2

12 + 7i - 12(-1)

12 + 7i + 12

24 + 7i

6

Simplify:

Explanation

Rewrite in their imaginary terms.

7

has 4 roots, including the complex numbers. Take the product of with each of these roots. Take the sum of these 4 results. Which of the following is equal to this sum?

The correct answer is not listed.

Explanation

This gives us roots of

The product of with each of these gives us:

The sum of these 4 is:

What we notice is that each of the roots has a negative. It thus makes sense that they will all cancel out. Rather than going through all the multiplication, we can instead look at the very beginning setup, which we can simplify using the distributive property:

8

Define an operation such that, for any complex number ,

If , then evaluate .

Explanation

, so

, so

, and

Rationalize the denominator by multiplying both numerator and denominator by the complex conjugate of the latter, which is :

9

Simplify:

Explanation

Use FOIL:

Combine like terms:

But since , we know

10

Evaluate .

None of the other choices gives the correct response.

Explanation

Apply the Power of a Product Rule:

,

and

,

so, substituting and evaluating:

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