The second problem I am having is: a) solve x^2+7x-2=0
b) find the x intercepts of f(x)=x^2+7x-2 The answer I got for this one was -7+sqrt(5)/2 and -7-sqrt(5)/2. And it told me I was wrong...help.

Question

The second problem I am having is: a) solve x^2+7x-2=0
b) find the x intercepts of f(x)=x^2+7x-2  The answer I got for this one was -7+sqrt(5)/2 and -7-sqrt(5)/2.  And it told me I was wrong...help.

mertsj · Answer

Did you use the quadratic formula?  a = 1, b = 7, c = -2

anonymous · Answer

I thought I did.

mertsj · Answer

$$x=\frac{-7\pm \sqrt{49-4(1)(-2)}}{2}=\frac{-7\pm \sqrt{57}}{2}$$

anonymous · Answer

x=1/2(-7-(57)^1/2)
X=1/2((57)^1/2-7)