The quadratic formula states:
For color(red)(a)x^2 + color(blue)(b)x + color(green)(c) = 0, the values of x which are the solutions to the equation are given by:
x = (-color(blue)(b) +- sqrt(color(blue)(b)^2 - (4color(red)(a)color(green)(c))))/(2 * color(red)(a))
Substituting:
color(red)(1) for color(red)(a)
color(blue)(-34) for color(blue)(b)
color(green)(1) for color(green)(c) gives:
x = (-color(blue)(-34) +- sqrt(color(blue)(-34)^2 - (4 * color(red)(1) * color(green)(1))))/(2 * color(red)(1))
x = (34 +- sqrt(1156 - 4))/2
x = (34 +- sqrt(1152))/2
x = (34 - sqrt(576 * 2))/2 and x = (34 + sqrt(576 * 2))/2
x = (34 - sqrt(576)sqrt(2))/2 and x = (34 + sqrt(576)sqrt(2))/2
x = (34 - 24sqrt(2))/2 and x = (34 + 24sqrt(2))/2
x = 17 - 12sqrt(2) and x = 17 + 12sqrt(2)