SOLUTION: please check this for me? 7x^2+18-9 x=-b+-sqrt{{{b^2-4ac}}}/2a x=-18+-sqrt{{{18^2+4*7*9}}}/2*7 x=(-18+24)/2*7 x=6/14=3/7 x=-42/14=-3 x=-3,7

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: please check this for me? 7x^2+18-9 x=-b+-sqrt{{{b^2-4ac}}}/2a x=-18+-sqrt{{{18^2+4*7*9}}}/2*7 x=(-18+24)/2*7 x=6/14=3/7 x=-42/14=-3 x=-3,7      Log On


   

Question 81337: please check this for me?
7x^2+18-9
x=-b+-sqrtb%5E2-4ac/2a
x=-18+-sqrt18%5E2%2B4%2A7%2A9/2*7
x=(-18+24)/2*7
x=6/14=3/7
x=-42/14=-3
x=-3,7
Answer by vertciel(183) About Me  (Show Source):
You can put this solution on YOUR website!
Hello there,
x = 3/7 and x = -3 is correct.
You actually could have solved this question more easily, by factoring the quadratic:
(7x - 3)(x + 3)
Now you can see that x MUST be x = 3/7 and x = - 3.
Also, you could have graphed this quadratic with your calculator to see if your x -intercepts are right.