Simplify (-7x^2-4)+(-7x^2-6x-2)

$(- 7 x^{2} - 4) + (- 7 x^{2} - 6 x - 2)$

Remove parentheses.

$- 7 x^{2} - 4 - 7 x^{2} - 6 x - 2$

Subtract $7 x^{2}$ from $- 7 x^{2}$ .

$- 14 x^{2} - 4 - 6 x - 2$

Subtract $2$ from $- 4$ .

$- 14 x^{2} - 6 x - 6$