Answer:
Step-by-step explanation:
ax² + bx + c = 0
[tex]x_{1}[/tex] = [tex]\frac{-b - \sqrt{b^2 -4ac} }{2a}[/tex]
[tex]x_{2}[/tex] = [tex]\frac{-b+\sqrt{b^2 -4ac} }{2a}[/tex]
~~~~~~~~~~~~~~~~~~~
x² + 4x - 16 = 0
a = 1 , b = 4 , c = - 16
[tex]x_{1}[/tex] = ( - 4 - [tex]\sqrt{16+64}[/tex] ) ÷ 2 = - 2 - 4√5
[tex]x_{2}[/tex] = - 2 + 4√5
