Simplify x^2+2-1+6x^2-4x^2

$x^{2} + 2 - 1 + 6 x^{2} - 4 x^{2}$

Add $x^{2}$ and $6 x^{2}$ .

$7 x^{2} + 2 - 1 - 4 x^{2}$

Subtract $4 x^{2}$ from $7 x^{2}$ .

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

Subtract $1$ from $2$ .

$3 x^{2} + 1$