Question

what should be added to
$3x3 - 5x {}^{2} + 7x - 6$
to obtain
$x3 - 2x {}^{2} - x + 9$
??​

Answer 1

Answer:

$- 2 {x}^{3} + 3 {x}^{2} - 8x + 15$

Step-by-step explanation:

$(3 {x}^{3} - 5 {x}^{2} + 7x - 6) + ? = ( {x}^{3} - 2 {x}^{2} - x + 9) \\ ? = ( {x}^{3} - 2 {x}^{2} - x + 9) - ( {3x}^{3} - 5 {x}^{2} + 7x - 6) \\ ? = {x}^{3} - 2 {x}^{2} - x + 9 - 3 {x}^{3} + 5 {x}^{2} - 7x + 6 \\ ? = - 2 {x}^{3} + 3 {x}^{2} - 8x + 15$