Question

(-x^3 + 2x^2 - x + 5) - (--x^3 + 2x^2 - x + 5) = ???

Answer 1

(-x^3 + 2x^2 - x + 5) - (-x^3 + 2x^2 - x + 5) 

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

todo se eliminan

sale cero