Simplify (x^2-4x-1)+(-5+5x^2-3x)

$(x^{2} - 4 x - 1) + (- 5 + 5 x^{2} - 3 x)$

Remove parentheses.

$x^{2} - 4 x - 1 - 5 + 5 x^{2} - 3 x$

Add $x^{2}$ and $5 x^{2}$ .

$6 x^{2} - 4 x - 1 - 5 - 3 x$

Subtract $3 x$ from $- 4 x$ .

$6 x^{2} - 7 x - 1 - 5$

Subtract $5$ from $- 1$ .

$6 x^{2} - 7 x - 6$