Question

In this problem, what are the steps I need to use? Please help. (8x+5)(2x^2+9x+5)

Answer 1

(8x+5)(2x^2+9x+5)=
18x^3+72x^2+40x+10x^2+45x+25=
18x^3+82x^2+85x+25

Answer 2

are these the steps I need to take? or is it the answer?

Answer 3

\[(8x+5)(2x^2+9x+5)=8x(2x^2+9x+5)+5(2x^2+9x+5)\]

Answer 4

\[=8x(2x^2)+8x(9x)+8x(5)+5(2x^2)+5(9x)+5(5)\]

Answer 5

Do you see what I did so far?

Answer 6

I do.

Answer 7

Great!
Now it is just matter of using law of exponents and the fact that multiplication is commutative

Answer 8

Yes. It is the answer

Answer 9

and also associative
\[=8(2)x(x^2)+8(9)x(x)+8(5)x+6(2)x^2+5(9)(x)+5(5)\]

Answer 10

oh ok...

Answer 11

\[=16x^{2+1}+72x^{1+1}+40x+12x^2+45x+25\]

Answer 12

Oh wow, that last one looks confusing.

Answer 13

You don't have to do that step
I was just trying to use some basic rules

Answer 14

\[=16x^3+72x^2+40x+12x^2+45x+25\]
Combine like terms
and you will be done

Answer 15

But if you need me to go over that step with you again I will

Answer 16

\[=8x(2x^2)+8x(9x)+8x(5)+5(2x^2)+5(9x)+5(5) \]
This was the expression I had before I made it confusing for you I think right?

Answer 17

so we are combining like terms for the last step?

Answer 18

Yes! :)

Answer 19

Yes that was before it got confusing.

Answer 20

Ok so let me give this a shot then.

Answer 21

Ok...I will give you some time to yourself
and say something when you want me to come back k?

Answer 22

which one are we combining like terms for so I can make sure I have the right one wrote down.

Answer 23

\[=16x^3+72x^2+40x+12x^2+45x+25 \]

Answer 24

Ok i had the wrong one...give me a minute let me see what I get..

Answer 25

I am not so sure I got it right, but here is what I got. 185x^9+25

Answer 26

Oh no that is not right

Answer 27

Ok I didn't think so. I am not good at this stuff...

Answer 28

like terms are terms with the same variable part

Answer 29

Ok by variable you mean the "x" right?

Answer 30

You want to look for all the terms with x^3 (and add those together)
Then you want to look for all terms with x^2 (and add those together)
Then you want to look for all terms with x (and add those together)
And add any constant terms that are remaining together

Answer 31

Oh oK...trying again.

Answer 32

Ok go you! You can do it! :)

Answer 33

Ok trying again.

Answer 34

16x^3+84x^2+85x+25

Answer 35

+10000 points :)
Good job!

Answer 36

THANK YOU for showing me how to work it out!!!!!

Answer 37

But wait

Answer 38

I think I made a typing error above k?

Answer 39

ok...

Answer 40

\[=8x(2x^2)+8x(9x)+8x(5)+5(2x^2)+5(9x)+5(5) \]
We had this and I accidentally wrote
\[=8(2)x(x^2)+8(9)x(x)+8(5)x+6(2)x^2+5(9)(x)+5(5) \]
See how that one number changed from a 5 to a 6
my bad :(

Answer 41

\[=16x^3+72x^2+40x+10x^2+45x+25\]

Answer 42

Ok so need to try it again right? will make the answer different.

Answer 43

yes it will and sorry about that

Answer 44

Not a problem it happens. I got 16x^3+82x^2+85x+25

Answer 45

Bingo! Now you can take the points and be happy. lol

Answer 46

Thank You so much! Your a lot more patient than some of these people on here, and I like being showed how its worked out and not having the answer just given to me! Thanks again!!

Answer 47

You are totally welcome! :) I like people who want to learn the material so you are really awesome! Go you!
Have a good night!

Answer 48

You too!