simplifying polynomials

[jadjr2000]

i'm trying to simplify this equation by combining the like terms. 8y² + 4y³– 2y² + 3y³x + yx

i come up with 10y x²,

also tring to add the following expression to make it simple

3x³ - 4 + 8 – 2x³

thanks for stopping by

 

[Denis]

Are you a student attending math classes? What grade are you in?

 

[jadjr2000]

no, i am in a pub quiz league and saw these questions so I wrote them down, couldn't figure them out

 

[jadjr2000]

is my 2nd question posed which was 3x³ - 4 + 8 – 2x³ , add to give simplest result

answer i come up with is x3-4

 

[Denis]

is my 2nd question posed which was 3x³ - 4 + 8 – 2x³ , add to give simplest result
answer i come up with is x3-4

NO. First, -4 + 8 = 4, not -4 ; 4 - 8 would equal -4

3x^3 - 2x^3 = x^3 : you got that right!
So final answer: x^3 + 4

Remember: 3x^3 - 2x^3 is same as 3 apples minus 2 apples...

 

[jadjr2000]

ok, i should have put the plus instead of the minus. i didn't receive a response on the first part, which was :

i'm trying to simplify this equation by combining the like terms. 8y² + 4y³– 2y² + 3y³x + yx

i come up with 10y x²..