How do you move from standard form to the quadratic equation?

Standard form of the quadratic form is

ax^2+bx+c=0

so basically if you have

x+3=0 then

it is

0x^2+1x+3=0

if you had

x^2+3=4

subtract 4

x^2-1=0

1x^2+0x-1=0

if you have

x^2+3x=0 then

x^2+3x+0=0