Simplify (-10x^2-x+6)+(10x^2-5)

$(- 10 x^{2} - x + 6) + (10 x^{2} - 5)$

Remove parentheses.

$- 10 x^{2} - x + 6 + 10 x^{2} - 5$

Combine the opposite terms in $- 10 x^{2} - x + 6 + 10 x^{2} - 5$ .

Add $- 10 x^{2}$ and $10 x^{2}$ .

$- x + 6 + 0 - 5$

Add $- x + 6$ and $0$ .

$- x + 6 - 5$

Subtract $5$ from $6$ .

$- x + 1$