Question

resolva: -7y² +8y² -5y² -10y² -(-10y²)

Answer 1

$(-7y^2-5y^2-10y^2)+(8y^2+10^2)\\ -22y^2+18y^2\\ -4y^2\\ y^2=4\\ y=\pm\sqrt{4}\\\\ \boxed{y'=2}\ e\ \boxed{y''=-2}$

Bons estudos!