# When x^2 +3x-4 is subtracted from x^ 3+3x^2 -2x what is the difference?

Nov 25, 2016

${x}^{3} + 2 {x}^{2} - 5 x + 4$

#### Explanation:

To find the difference, write the equation as:

$\left({x}^{3} + 3 {x}^{2} - 2 x\right) - \left({x}^{2} + 3 x - 4\right)$

Open the brackets, changing the sign according to the norm (multiplication of two negatives gives a positive, and of a negative and a positive gives a negative).

${x}^{3} + 3 {x}^{2} - 2 x - {x}^{2} - 3 x + 4$

Group the like terms.

${x}^{3} + 3 {x}^{2} - {x}^{2} - 2 x - 3 x + 4$

Combine like terms, taking note of the appropriate signs.

${x}^{3} + 2 {x}^{2} - 5 x + 4$