doiink
Jul 4 2008, 11:47 AM
ax^2+bx+c=0
(-b + √ (b^2 - 4ac))/2a
for the equation X^2+14X-5=0
a = 3
b = 14
c = -5
so substitute the values in:
[-14 + √ (14^2 - 4(3)(-5) ] /2(3)
[-14 +√( 196 + 60)] /6
[-14+√(256)] /6
and because the quadratic equation is +, you need to use the equation once with addition, and once with subtraction
[-14+√(256)] /6 = -.333
[-14 - √(256)] /6 = -5