# High School Math : How to combine like terms with negative numbers in pre-algebra

## Example Questions

### Example Question #91 : High School Math

What is the value of ?

13

8

-1

1

9

9

Explanation:

Adding and subtracting negative integers is confusing if you don't use parentheses right.  As long as you remember to keep them in the right places and stay neat, it is easy.  Subtracting negative numbers is the same as adding a positive number, and adding a negative number is the same as subtracting a positive number.  So, we could rewrite the equation like this:

### Example Question #2 : How To Combine Like Terms With Negative Numbers In Pre Algebra

What is  simplified?

Explanation:

To simplify a problem like the example above we must combine the like termed variables.

Like terms are the numbers that have the same variable, in this example,  and .

Separate the s to get

Then perform the necessary addition to get

Then separate the ’s to get

Then perform the necessary subtraction to get

We then combine our answers to have the simplified version of the equation .

### Example Question #1 : How To Combine Like Terms With Negative Numbers In Pre Algebra

If , what is ?

Explanation:

Subtract  from both sides:

Combine our s:

Divide both sides by :

However, the problem is asking for  not , so multiply both sides by :

### Example Question #2 : How To Combine Like Terms With Negative Numbers In Pre Algebra

Simplify the following equation by combining like terms:

Explanation:

X is the only term that appears twice in the equation.  Since both are positive numbers, we can add the X terms to simplify the equation.

### Example Question #1 : How To Combine Like Terms With Negative Numbers In Pre Algebra

Combine the like terms for .

Explanation:

Remember, adding a negative number is the same as subtracting a positive number. That means we can think of this problem as .

If we think of this on a number line, we start at , move left three units because of the , then move left again by one more unit for the , giving us a total of .

### Example Question #1 : How To Combine Like Terms With Negative Numbers In Pre Algebra

Simplify:

Explanation:

Here, we are interested in combining like terms. Like terms are those with the same variable,.

When combining terms with in them, we add the coefficients. Thus, we have , and

Therefore, we have .

### Example Question #3 : How To Combine Like Terms With Negative Numbers In Pre Algebra

Simplify:

Explanation:

Combine like terms:

= (5 + 7) + (-2x - 4x - 9x)

= 12 + (-15x)

= 12 - 15x

Simplify: