Question

Simplify:





8x3 – 2x2 + x + 3x3



A.


10x3


B.


11x3– 2x2+ x


C.


11x6– 2x2+ x


D.


8x3– 2x2+ x + 3x3 (the expression cannot be simplified)

@ganeshie8
@ luigi0210

Answer 1

will medal and fan

Answer 2

When looking at \[ 8x^3-2x^2+x+3x^3\], you want to try to combine like terms. What like terms do you see?

Answer 3

8x3 and 2x3 and 3x3

@onemillion6

Answer 4

8x^3 and 3x^3 are like terms, yes! (But -2x^2 is not because it has a different power on the x. You want the exponents to match.) Now, we can rewrite what is given above as \[ 8x^3+3x^3-2x^2+x\]
(just switching the order)

You combine 8x^3+3x^3 but adding the coefficients together. So what is 8x^3+3x^3?

Answer 5

would it be 10^3+3^3

Answer 6

Not quite. One way to think about 8x^3+3x^3 is:
\[ (x^3+x^3+x^3+x^3+x^3+x^3+x^3+x^3)+(x^3+x^3+x^3)\]
There are 8 x^3's in the group inside the first parentheses and 3 in the second group. That is what 8x^3+3x^3.

Looking at the equation above, how many x^3's are there in total?

Answer 7

8^3+3^3?

Answer 8

Ah. I think I get what you're trying to do. When you combine like terms, the x's don't just go away. So the sum you're looking for is going to be something like:
(a number)x^3

What if I write it like this:
\[ 8x^3+3x^3 = x^3(8+3) = ? \]
Can you complete the equation?

Answer 9

11^3?

Answer 10

11x^3! Don't leave out the x. But, correct :)

So your new expression is
\[ 11x^3 -2x^2 + x \]
Do you see that in your answer choices?

Answer 11

yes

Answer 12

hooray, then you'er done :)