### All ISEE Middle Level Math Resources

## Example Questions

### Example Question #31 : How To Subtract Variables

Simplify the following:

**Possible Answers:**

**Correct answer:**

To subtract variables, we will think of the variables as objects. So, in the problem

let's think of the variable *y* as pens. So, we can look at the problem as we currently have 9 pens. We let our friends borrow 3 pens. How many pens do we have now? The answer is 6. We now have 6 pens.

We can subtract the variables in the same way. So,

### Example Question #32 : How To Subtract Variables

Simplify the following:

**Possible Answers:**

**Correct answer:**

To subtract variables, we will look at the variables as objects. So,

we can look at it as the following. We have 5 dollars. We go to the store and buy something and spend 2 dollars. How many dollars do we have now? We now have 3 dollars. We subtract variables in the same way. So

### Example Question #820 : Concepts

Simplify:

**Possible Answers:**

**Correct answer:**

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.

### Example Question #33 : How To Subtract Variables

Simplify:

**Possible Answers:**

**Correct answer:**

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 on to the next step

Multiplication: We can distribute the negative sign to the and

Remember, a negative times a negative will equal a positive, so we have a

Finally we can combine like terms

### Example Question #34 : How To Subtract Variables

Simplify the following:

**Possible Answers:**

**Correct answer:**

To subtract variables, we will think of the variables as objects. So, given

we can think of *x* as grapes. So, we start with 10 grapes. If we eat 2 grapes, how many grapes do we have now? We have 8 grapes. We can subtract variables the same way.

### Example Question #35 : How To Subtract Variables

Simplify the following statement:

**Possible Answers:**

**Correct answer:**

Simplify the following statement:

We have two terms, each with the same exponent. We can complete this problem by subtracting the coefficients just as we would do any other subtraction

So our answer is just

### Example Question #36 : How To Subtract Variables

Subtract the following:

**Possible Answers:**

**Correct answer:**

To subtract variables, we will look at the variables like objects. So in the problem

we will think of *b* as being balloons. So we can read this problem as

So, if we have 8 balloons, and we give away 2 balloon, how many balloons do we have now?

We subtract variables the same way. So,

We can look at this as we have 8 of something, if we subtract 2 of those somethings, how many do we have now?

### Example Question #37 : How To Subtract Variables

Subtract the following:

**Possible Answers:**

**Correct answer:**

When subtracting variables, we can look at the variables as objects, then subtract those objects.

We can think of the variable *b* as bananas. So, we can look at it as

We can think of it like this: If we buy 9 bananas at the store, and we eat 2 bananas, how many bananas do we have now? We have 7 bananas left. So,

We subtract variables the same way.

### Example Question #38 : How To Subtract Variables

Solve the following:

**Possible Answers:**

**Correct answer:**

When subtracting variables, we can think of the variables as objects. So, in the problem

we can think of the variable *c* as cookies. So, we can write it like

We can think of it like this: There are 12 cookies on a plate. We eat 2 of the cookies. How many cookies are left? There are 10 cookies left on the plate.

So, we get

We subtract variables the same way:

### Example Question #39 : How To Subtract Variables

Solve the following:

**Possible Answers:**

**Correct answer:**

To subtract variables, we will think of the variables as objects. So, in the problem

we can think of the variable *b* as bottles of water. So, we can write it like

We can think of it like this: A cooler has 10 bottles of water. You take 1 bottle of water from the cooler. How many bottles of water are left in the cooler? There are 9 bottles of water in the cooler. So,

We subtract variables the same way:

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