### All GRE Math Resources

## Example Questions

### Example Question #1 : How To Subtract Fractions

Solve for :

**Possible Answers:**

**Correct answer:**

Begin by isolating the factors:

Now, the common denominator of these two fractions is . Therefore, multiply by :

Now, you can subtract the left values:

Now, multiply both sides by :

### Example Question #1 : Operations

Quantity A:

Quantity B:

Which of the following is true?

**Possible Answers:**

Quantity B is larger.

The two quantities are equal.

The relationship between the quantities cannot be determined.

Quantity A is larger.

**Correct answer:**

Quantity A is larger.

First, consider each quantity separately.

**Quantity A**

These two fractions do not have a common factor. Their common denominator is . Thus, we multiply the fractions as follows to give them a common denominator:

This is the same as:

**Quantity B**

The common denominator of these two values is . Therefore, you multiply the fractions as follows to give them a common denominator:

This is the same as:

Since Quantity A is larger than and Quantity B is a positive fraction less than , we know that Quantity A is larger without even using a calculator.

### Example Question #1 : Operations

Simplify:

**Possible Answers:**

**Correct answer:**

Just like adding fractions, when you subtract fractions, you need to find a common denominator. For and , the least common denominator is . In order to do your subtraction, you need to multiply appropriately to give your fractions this denominator:

Which is the same as...

Now, you can subtract the numerators and retain the denominator: