SOLUTION: rewrite without the parentheses (2x+3)4

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Question 282922: rewrite without
the parentheses (2x+3)4

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!


%282x%2B3%29%5E4 Start with the given expression

To expand this, we're going to use binomial expansion. So let's look at Pascal's triangle:
1   

1   1   

1   2   1   

1   3   3   1   

1   4   6   4   1   




Looking at the row that starts with 1,4, etc, we can see that this row has the numbers:

1, 4, 6, 4, and 1

These numbers will be the coefficients of our expansion. So to expand %282x%2B3%29%5E4, simply follow this procedure:
Write the first coefficient. Multiply that coefficient with the first binomial term 2x and then the second binomial term 3. Repeat this until all of the coefficients have been written.

Once that has been done, add up the terms like this:


Notice how the coefficients are in front of each term.



However, we're not done yet.


Looking at the first term 1%282x%29%283%29, raise 2x to the 4th power and raise 3 to the 0th power.

Looking at the second term 4%282x%29%283%29 raise 2x to the 3rd power and raise 3 to the 1st power.

Continue this until you reach the final term.


Notice how the exponents of 2x are stepping down and the exponents of 3 are stepping up.


So the fully expanded expression should now look like this:





Distribute the exponents


1%2816x%5E4%29%2B4%2824x%5E3%29%2B6%2836x%5E2%29%2B4%2854x%29%2B1%2881%29 Multiply


16x%5E4%2B96x%5E3%2B216x%5E2%2B216x%2B81 Multiply the terms with their coefficients


So %282x%2B3%29%5E4 expands and simplifies to 16x%5E4%2B96x%5E3%2B216x%5E2%2B216x%2B81.


In other words, %282x%2B3%29%5E4=16x%5E4%2B96x%5E3%2B216x%5E2%2B216x%2B81