Look at the quadratic equation below. -x2 + 3 = (2x - 1)2 what is this quadratic equation written in standard form?

We need to expand it
standard is 0=ax^2+bx+c

so
expand left side
(2x-1)²=(2x-1)(2x-1)=4x²-4x+1
now we gots
-x²+3=4x²-4x+1
add x^2 to both sides and minus 3
0=5x²-4x-2