SOLUTION: I need help solving two problems. Using the quadratic formula. x^2 - 3x - 1 = 0 (a=1, b= -3 and c = -1 4x^2 + x - 1 = 0 (a =4, b=1, and c = -1

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: I need help solving two problems. Using the quadratic formula. x^2 - 3x - 1 = 0 (a=1, b= -3 and c = -1 4x^2 + x - 1 = 0 (a =4, b=1, and c = -1      Log On


   

Question 554548: I need help solving two problems. Using the quadratic formula.
x^2 - 3x - 1 = 0 (a=1, b= -3 and c = -1
4x^2 + x - 1 = 0 (a =4, b=1, and c = -1
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
x² - 3x - 1 = 0 (a=1, b=-3 and c=-1

x = %28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ 

x = %28-%28-3%29+%2B-+sqrt%28+%28-3%29%5E2-4%2A%281%29%2A%28-1%29+%29%29%2F%282%2A%281%29%29+

x = %283+%2B-+sqrt%289%2B4+%29%29%2F2+

x = %283+%2B-+sqrt%2813%29%29%2F2+


Two solutions,

x = %283+%2B+sqrt%2813%29%29%2F2+ and x = %283+-+sqrt%2813%29%29%2F2+

------------------------------
4x² + x - 1 = 0 (a=4, b=1, and c=-1

x = %28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ 

x = %28-%281%29+%2B-+sqrt%28+%281%29%5E2-4%2A%284%29%2A%28-1%29+%29%29%2F%282%2A%284%29%29+

x = %28-1+%2B-+sqrt%281%2B16+%29%29%2F8+

x = %28-1+%2B-+sqrt%2817%29%29%2F8+


Two solutions,

x = %28-1+%2B+sqrt%2817%29%29%2F8+ and x = %28-1+-+sqrt%2817%29%29%2F8+


Edwin