What must be added to 4x^3 - 3x^2 + 2 to give 3x^3 + 7x - 6?

The answer is -x^3 + 3x^2 + 7x - 8

The only parts I don't understand are why there is a + before 3x^2 and why there is a + before 7x. How exactly do we work that out, we aren't adding it to anything?

Question

What must be added to 4x^3 - 3x^2 + 2 to give 3x^3 + 7x - 6? 

The answer is -x^3 + 3x^2 + 7x - 8

The only parts I don't understand are why there is a + before 3x^2 and why there is a + before 7x. How exactly do we work that out, we aren't adding it to anything?

anonymous · Answer

when we add +4x^3 wid -X^3 the sign will be poaitive bcoz sign is always prefferd wid higher no.i.e. here 4 is greater than 1 and 4 has a positive sign so result will be positive

anonymous · Answer

I'm having trouble with why it is +3x^2 + 7x.

ganeshie8 · Answer

$\large  4x^3 - 3x^2 + 2 + \color{red}{\text{something}} =  3x^3 + 7x - 6 $

ganeshie8 · Answer

subtract  $\large  4x^3$ both sides

ganeshie8 · Answer

$\large  4x^3 - 3x^2 + 2 + \color{red}{\text{something}} =  3x^3 + 7x - 6 $

subtract $\large 4x^3 $  both sides

$\large  - 3x^2 + 2 + \color{red}{\text{something}} =  -x^3 + 7x - 6 $

ganeshie8 · Answer

fine so far ? :)

anonymous · Answer

Oh, I get it now! Thanks so much!

ganeshie8 · Answer

good to hear :)