Math Is Fun Forum

Thank you I understand that part but when I do that and apply the Quadratic formula, I do not get anywhere near the answer my textbook has.  There answer is X= 7.440307.

Here is my work:

x(x+6)=100
x^2+6x-100=0

a=1  b=6  c=-100

-6+or- sqr 6^2-4(1)(-100)/2=20.38

Do you know where I have gone wrong
ty

Bob