ISEE Middle Level Math : How to add variables

Study concepts, example questions & explanations for ISEE Middle Level Math

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Example Questions

Example Question #51 : How To Add Variables

Combine the following:

Possible Answers:

Correct answer:

Explanation:

When adding variables, we will look at the variables like objects.  So, in the problem

we can think of p as pancakes.  So, we can write it like

We can read the problem like this:  We are eating breakfast.  We are very hungry, and we decided to eat 2 pancakes.  We are still hungry, so we eat 3 more pancakes.  How many pancakes have we eaten for breakfast? We have eaten 5 pancakes.

We can add variables the same way.

Example Question #52 : How To Add Variables

Combine the following:

Possible Answers:

Correct answer:

Explanation:

To add variables, we will look at the variables like they are objects.  So, in the problem

we can think of the variable p as pretzels.  So, we can write it like

We can read the problem like this:  We eat 2 pretzels.  They are really good, so we eat 5 more pretzels.  How many pretzels have we eaten in total?  We have eaten 7 pretzels.

 

We can add variables the same way.  So,

Example Question #53 : How To Add Variables

Combine the following:

Possible Answers:

Correct answer:

Explanation:

When adding terms with variables, we can only combine the terms with like variables.  So, we get

Example Question #54 : How To Add Variables

Combine the following:

Possible Answers:

Correct answer:

Explanation:

To add variables, we will combine like variables together.  We can also think of the variables as objects.  

For example, a could be apples, and b could be balloons.  So, we could write

Example Question #55 : How To Add Variables

Simplify this equation.

Possible Answers:

Correct answer:

Explanation:

To solve this problem you must combine all of the like terms.

So we add 

.

Then we add those together to simplify the expression to 

.

Example Question #56 : How To Add Variables

Solve for .

Possible Answers:

Correct answer:

Explanation:

First, combine all like terms, so we are left with 

.

Then to isolate the variable (get it alone), we divide each side by 10 and are left with 

.

Example Question #57 : How To Add Variables

Simplify by combining like terms.

Possible Answers:

Correct answer:

Explanation:

Simplify by combining like terms.

We can begin by reordering our variables to have ones with the same exponent next to eachother.

Then, simply add the cofficients (numbers in front of the variables) of any variable with the same exponent

So our answer is:

Example Question #54 : How To Add Variables

Simplify:

Possible Answers:

Correct answer:

Explanation:

You should begin by distributing  through the whole group that it precedes:

Now, move your like variables next to each other:

Finally, combine the like terms:

Example Question #11 : Expressions & Equations

Simplify the following:

Possible Answers:

Correct answer:

Explanation:

When solving this problem we need to remember our order of operations, or PEMDAS. 

PEMDAS stands for parentheses, exponents, multiplication/division, and addition/subtraction. When you have a problem with several different operations, you need to solve the problem in this order and you work from left to right for multiplication/division and addition/subtraction.

Parentheses: We are not able to add a variable  to a number, so we move to the next step. 

Multiplication: We can distribute (or multiply) the 

Addition/Subtraction: Remember, we can't add a variable  to a number, so the  is left alone.

Now we have 

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