GED Math : GED Math

Study concepts, example questions & explanations for GED Math

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Example Questions

Example Question #1 : Exponents

Simplify: 

Possible Answers:

Correct answer:

Explanation:

Example Question #3 : Exponents

Express 45,000,000 in scientific notation.

Possible Answers:

Correct answer:

Explanation:

Write the number with a decimal point and without commas:

Counting the number of places, move the decimal point to the left until it is after the first nonzero digit:

The resulting  number is 4.5; the number of places the decimal point moved to the left was 7. In scientific notation, this number is .

Example Question #3 : Exponents

Express 0.000000038 in scientific notation.

Possible Answers:

Correct answer:

Explanation:

Write the number:

Counting the number of places, move the decimal point to the right until it is after the first nonzero digit:

The resulting  number is 3.8; the number of places the decimal point moved to the right was 8. In scientific notation, this number is .

Example Question #2 : Exponents

Which of the following is not equal to  ?

Do not use a calculator.

Possible Answers:

Correct answer:

Explanation:

A positive number raised to any real power is positive.  and  are the opposites of powers of positive numbers; they are therefore the opposites of positive numbers, making both negative.

A negative number raised to an odd power, such as , is negative.

A negative number raised to an even power, such as , is positive. 

 is the only positive number among the choices and can be deduced as the correct choice.

 

Example Question #3 : Exponents

Without using a calculator, evaluate .

Possible Answers:

Correct answer:

Explanation:

For any nonzero  and for any . Equivalently, any number raised to a negative power is equal to the reciprocal of that number raised to the power of the absolute value of the exponent.

The reciprocal of a number is the quotient of 1 and the number, so the reciprocal of 0.4 is 

.

Therefore, 

, which is the correct response.

Example Question #4 : Exponents

Evaluate without using a calculator: 

Possible Answers:

Correct answer:

Explanation:

 

Example Question #5 : Exponents

Simplify the expression:

Possible Answers:

Correct answer:

Explanation:

A number or variable can be raised to a negative power by taking the reciprocal of the same number raised to the power of the absolute value of the exponent.

Example Question #1 : Exponents

Without using a calculator, evaluate:

Possible Answers:

Correct answer:

Explanation:

For any nonzero  and for any . Equivalently, any number raised to a negative power is equal to the reciprocal of that number raised to the power of the absolute value of the exponent. Apply this power, along with the power of a quotient property: 

Example Question #11 : Exponents

Order from least to greatest:

Do not use a calculator.

Possible Answers:

Correct answer:

Explanation:

For any nonzero  and for any .

 

Since 

we can reverse the order when taking their reciprocals:

That is, .

Example Question #11 : Exponents

Order from least to greatest:

Do not use a calculator.

Possible Answers:

Correct answer:

Explanation:

For any nonzero  and for any .

Also, any negative number raised to the power of an odd number is equal to the opposite of the same power of its absolute value.

Combine these concepts:

Since ,

the reciprocals are in reverse order of this:

Their opposites reverse again:

Or, equivalently,

.

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