Respuesta :

[tex]\bf f(x)=-5x^2+2x-1\implies f(a)=-5(a)^2+2(a)-1 \\\\\\ f(a)=-5a^2+2a-1 \\\\\\ -f(a)\implies -~[-5a^2+2a-1]\implies 5a^2-2a+1[/tex]