quadratic formula is:
-b - sqrt(b^2-4ac)
x = ---------------------
2a
or: -b + sqrt(b^2-4ac)
x = ---------------------
2a
your equation is in standard form ax^2 + bx + c = 0
a is the coefficient of the x^2 term.
b is the coefficient of the x term.
c is the contant term.
your equation is x^2 - 0.011x - 0.064 = 0
that means that:
a = 1
b = -.011
c = .064
just replace the variables in the equation and solve for x.
you will get:
x = -.24754199.... or x = .25854199...
round as required.
you could also have graphed this equation using a graphing calculator and would have gotten the same answer.
here's the graph that i did.
