separation

ax2+bx+c=a(x+b2a)2+(4acb24a)a\cdot x^{2}+b\cdot x+c = a\cdot (x+\frac{b}{2\cdot a})^{2}+(4\cdot a\cdot c-\frac{b^{2}}{4\cdot a})
Find   It is known that:
      =