Question

Simplify (5x3- x + 14) - (3x2- 9x + 4)

A 5x3- 3x2+ 8x + 10
B 2x2+ 8x + 10
C 5x3- 3x2- 10x + 18
D 2x2- 10x + 18

This one im slightly confused on..
I think it would be B?
(im not guessing by the way.)

Answer 1

Another one involving the distributive property and combining like terms.

You have to distribute the subtraction to each term. View it like this:

(5x^3 - x + 14) + -1(3x^2 - 9x + 4)

Then distribute the -1 by multiplying it into each term.

(5x^3 - x + 14) + (-3x^2 + 9x - 4)

Then we can get rid of the parentheses.

5x^3 - x + 14 + -3x^2 + 9x - 4

Simplify that addition of a negative to subtraction:

5x^3 - x + 14 - 3x^2 + 9x - 4

Combine like terms:

5x^3 - 3x^2 - x + 10

Answer 2

Whoops I'm an idiot again:

5x^3 - 3x^2 + 8x + 10

Answer 3

lol, its okay. haha

Answer 4

You should be able to see that I lost track of the term "9x" between the second-to-last and last steps

Answer 5

I do actually see that, you really are helping me. :P

Answer 6

Your answer, b, is close, but not right- you can't subtract 3x^2 from 5x^3 because the terms have different degrees! They would both have to be ^2 or ^3 to do that.

Answer 7

would it be + 18x ? or minus 10x + 18

Answer 8

Thats exactly what i was confused on too, i think i got that now..

Answer 9

So can you explain how you got 18x and -10x + 18?

Answer 10

A

Answer 11

Yeah, the answer is A

Answer 12

Yeah i just realized my mistake.. Thanks again.