Respuesta :
x^2 + 4x - 16 = 0
I'm using the quadratic formula to solve this equation.
A = 1
B = 4
C = -16
x = -b +- [tex]\sqrt{b^2 - 4ac}[/tex]
over 2a
Plug it in:
x= -4 +- [tex]\sqrt{4^2 -4(-16)}[/tex] over 2
x= -4 +- [tex]\sqrt{16+64[/tex] over 2
x = -4 +-[tex]\sqrt{80}[/tex] over 2
x = -4 +- 4[tex]\sqrt{5[/tex]
Divide by 2.
x = -2 +- 2[tex]\sqrt{5[/tex]
Therefore, x would be -2 + 2[tex]\sqrt{5}[/tex], -2 - 2[tex]\sqrt{5}[/tex]
Convert to decimal form: 2.47213595, -6.47213595
Round it: 2.4714595 = 2.5 and -6.47213595 = -6.5