find the solution (rounded to tenths place) of thefollowing equation: x^2-7x-15=0 ben trying to work this problem out, answers dont match up. please help.

Question

anonymous · Answer

Quadratic formula

x =   7 +- sqrt(49 - 4(1)(-15)
       ----------------------
                        2

x = 7 +- sqrt(109)
    --------------
             2

x = 7 +- 10.4
      -----------
             2

x = 17.4/2    and   -3.4/2
x = 8.7 or x = -1.7