The vertex form of the equation of a parabola is y=2 (x+4)^2-21. What is the standard form of the equation?

for a quadratic, is simply the quadratic itself expanded, nothing to it, so we'll just simply expand the binomial and simplify,

[tex]\bf y=2(x+4)^2-2\implies y=2(x^2+8x+16)-2 \\\\\\ y=2x^2+16x+32-2\implies y=2x^2+16x+30[/tex]