Pre-Algebra : Addition and Subtraction

Study concepts, example questions & explanations for Pre-Algebra

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Example Questions

Example Question #131 : Operations

Perform the indicated mathematical operations: 

Possible Answers:

Correct answer:

Explanation:

In this problem we have two different types of terms. Those with x and without it. These two cannot be combined, but the fractions can. First we find a common denominator by multiplying one fraction by a number over itself that gives common denominators.

Now subtract the fractions:

Since the 5 term does not have an x we cannot combine the two.

Example Question #133 : Operations And Properties

Add:  

Possible Answers:

Correct answer:

Explanation:

Add the ones digit.

This is the ones digit of the final answer.

Add the tens digit.

The ones digit is the tens digit of the final answer.

Since there is a tens digit in this number, carry over the tens digit to the next calculation.

Add the hundreds digit with the carry over.

This number will represent the thousands and hundreds digit.

Combine the numbers.

The answer is:  

Example Question #11 : Addition And Subtraction

Solve:  

Possible Answers:

Correct answer:

Explanation:

Solve the inside of the parentheses. Then remove all the parentheses by distributing the negative signs.

The correct answer is .

Example Question #12 : Addition And Subtraction

Compute:  

Possible Answers:

Correct answer:

Explanation:

Solve  term by term.

The correct answer is .

Example Question #13 : Addition And Subtraction

Add .

Possible Answers:

Correct answer:

Explanation:

Add the ones digit.

The ones digit is the ones digit of the final answer.  Since there is a one in the tens digit, this is the carry over for the next calculation.

Add the tens digit with the carryover.

Combine all the numbers.  The answer is .

Example Question #15 : Addition And Subtraction

Solve:  

Possible Answers:

Correct answer:

Explanation:

Subtract the ones digit.  Borrow a one from the tens digit.

After borrowing a one from the , the tens digit of  will be .

Subtract the tens digit.

The answer is:  

Example Question #14 : Addition And Subtraction

Add:  

Possible Answers:

Correct answer:

Explanation:

Add the ones digits.

Add the tens digits.

Combine the two digits.

The answer is .

Example Question #17 : Addition And Subtraction

Subtract:  

Possible Answers:

Correct answer:

Explanation:

The ones digit cannot be subtracted as is.  We cannot borrow a one from the tens digit.  Borrow a one from the  of both the tens and the hundreds digit of .

This is the ones digit of the final answer.

Because a one was borrowed, the tens digit of  will be come a , and the hundreds digit will become zero.  Subtract the tens digits.

The correct answer is .  Adding 82 and 19 will give 101 as the answer.

Example Question #15 : Addition And Subtraction

Add:  

Possible Answers:

Correct answer:

Explanation:

Simplify the parentheses.  

A positive and a negative sign will result in a negative sign.

When all numbers are negative that are being added, simply add the integers and then place the negative sign in front of the final answer.

Example Question #19 : Addition And Subtraction

Add .

Possible Answers:

Correct answer:

Explanation:

Add the ones digit.

Since this number is 10 or greater, we must carry over the tens digit to the next calculation.

Add the tens digit with the carry over.

There is no carry over.

Add the hundreds digits.  The hundreds digit for  is zero.

Combine all ones digits.

The answer is .

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