How do you find the product of (9x + 4)^2(9x+4)2?

1 Answer
Apr 12, 2017

81x^2 + 72x + 16 81x2+72x+16

Explanation:

To simplify this expression, or any expression, a good start would be writing it out completely and getting rid of the exponent. This will make it a lot easier to multiply.

(9x + 4)^2 (9x+4)2 will become (9x + 4)(9x + 4) (9x+4)(9x+4)

Now we can begin to multiply by using the FOIL method.

Take the color(blue)"first term in the first binomial" first term in the first binomial and multiply it with color(green)"every term in the second binomial" every term in the second binomial.

Then take the color(red)"second term in the binomial" second term in the binomial and multiply it with color(green)"every term in the second binomial" every term in the second binomial.

(9x + 4)(9x + 4) (9x+4)(9x+4)

(color(blue)(9x) + 4)(color(green)(9x) + 4) (9x+4)(9x+4) color(orange)(->) 9x * 9x color(orange)(->) color(red)(81x^2) 9x9x81x2

(color(blue)(9x) + 4)(9x (9x+4)(9x color(green)( + 4)) +4) color(orange)(->) 9x * 4 color(orange)(->) color(red)(36x) 9x436x

(9x (9x color(red)( + 4))(color(green)(9x) + 4) +4)(9x+4) color(orange)(->) 4 * 9x color(orange)(->) color(red)(36x) 49x36x

(9x (9x color(red)( + 4))(9x +4)(9x color(green)( + 4)) +4) color(orange)(->) 4 * 4 color(orange)(->) color(red)(16) 4416

Now all we have to do is add the terms that we got and simplify.

81x^2 + 36x +36x + 16 81x2+36x+36x+16
81x^2 + 72x + 16 81x2+72x+16

As you can see, when we simplify our initial expression, we get our answer which is 81x^2 + 72x + 16 81x2+72x+16.