# How do you expand #(5y^4-x)^3#?

##### 1 Answer

See below

#### Explanation:

Write it out:

**3**

Step 1:

Pick **either TWO** brackets to expand it.

I would pick

This is how you expand them:

So,

**BE VERY CAREFUL WITH NEGATIVES!!**

Step 2: Now fully simplify the expanded equation

Simplify

Look out for like terms! There are two like

Your simplified equation should look like

**BE VERY CAREFUL WITH NEGATIVES!!**

Step 3: Now multiply your "expanded and simplified" two brackets with the remaining third bracket.

Break the third bracket up (that you did not touch) into

Step 4: Expand them and add them up.

**BE VERY CAREFUL WITH NEGATIVES!!**

Expand

Now expand

Now add them up:

Step 5: Last but not least, simplify them & add the like terms together.

Look closely at the equation and you can see one like term which is

Add the like terms together.

Your final equation should look like: