Squaring / Square Roots / Radicals - ACT Math

Card 0 of 20

Question

Suppose and

Evaluate the following expression:

Answer

Substituting for and , we have

This simplifies to

which equals

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Question

What is the sum of and given

and

?

Answer

A complex number is a combination of a real and imaginary number. To add complex numbers, add each element separately.

In equation , is the real component and is the imaginary component (designated by ).

In equation , is the real component and is the imaginary component.

When added,

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Question

What is the solution of the following equation?

Answer

A complex number is a combination of a real and imaginary number. To add complex numbers, add each element separately.

First, distribute:

Then, group the real and imaginary components:

Solve to get:

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Question

Complex numbers take the form , where a is the real term in the complex number and bi is the nonreal (imaginary) term in the complex number.

Simplify:

Answer

When adding or subtracting complex numbers, the real terms are additive/subtractive, and so are the nonreal terms.

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Question

Complex numbers take the form , where a is the real term in the complex number and bi is the nonreal (imaginary) term in the complex number.

Can you add the following two numbers: ? If so, what is their sum?

Answer

Complex numbers take the form a + bi, where a is the real term in the complex number and bi is the nonreal (imaginary) term in the complex number. Taking this, we can see that for the real number 8, we can rewrite the number as , where represents the (zero-sum) non-real portion of the complex number.

Thus, any real number can be added to any complex number simply by considering the nonreal portion of the number to be .

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Question

Complex numbers take the form , where is the real term in the complex number and is the nonreal (imaginary) term in the complex number.

Which of the following is incorrect?

Answer

Complex numbers take the form , where is the real term in the complex number and is the nonreal (imaginary) term in the complex number.

Thus, to balance the equation, add like terms on the left side.

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Question

Simplify:

Answer

This problem can be solved in a way similar to other kinds of division problems (with binomials, for example). We need to get the imaginary number out of the denominator, so we will multiply the denominator by its conjugate and multiply the top by it as well to preserve the number's value.

Then, recall by definition, so we can simplify this further:

This is as far as we can simplify, so it is our final answer.

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Question

Simplify:

Answer

Multiply both numberator and denominator by :

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Question

Evaluate:

Answer

First, divide 100 by as follows:

Now dvide this result by :

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Question

Evaluate:

Answer

First, divide 100 by as follows:

Now, divide this by :

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Question

Evaluate:

Answer

First, evaluate :

Now divide this into :

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Question

Evaluate:

Answer

First, evaluate using the square pattern:

Divide this into :

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Question

Complex numbers take the form , where is the real term in the complex number and is the nonreal (imaginary) term in the complex number.

Simplify:

Answer

This problem can be solved very similarly to a binomial such as . In this case, both the real and nonreal terms in the complex number are eligible to be divided by the real divisor.

, so

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Question

Complex numbers take the form , where is the real term in the complex number and is the nonreal (imaginary) term in the complex number.

Simplify by using conjugates:

Answer

Solving this problem using a conjugate is just like conjugating a binomial to simplify a denominator.

Multiply both terms by the denominator's conjugate.

Simplify. Note .

Combine and simplify.

Simplify the numerator.

The prime denominator prevents further simplifying.

Thus, .

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Question

Which real number satisfies ?

Answer

Simplify the base of 9 and 27 in order to have a common base.

(3x)(9)=272

= (3x)(32)=(33)2

=(3x+2)=36

Therefore:

x+2=6

x=4

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Question

Which of the following is a factor of ?

Answer

The terms of have as their greatest common factor, so

is a prime polynomial.

Of the five choices, only is a factor.

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Question

Which of the following expressions is equal to the following expression?

Answer

First, break down the component parts of the square root:

Combine like terms in a way that will let you pull some of them out from underneath the square root symbol:

Pull out the terms with even exponents and simplify:

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Question

Which of the following is equal to the following expression?

Answer

First, break down the components of the square root:

Combine like terms. Remember, when multiplying exponents, add them together:

Factor out the common factor of :

Factor the :

Combine the factored with the :

Now, you can pull out from underneath the square root sign as :

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Question

Which of the following expression is equal to

Answer

When simplifying a square root, consider the factors of each of its component parts:

Combine like terms:

Remove the common factor, :

Pull the outside of the equation as :

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Question

Simplify

Answer

The easiest way to approach this problem is to break everything into exponents. is equal to and 27 is equal to . Therefore, the expression can be broken down into . When you cancel out all the terms, you get , which equals .

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