Question

Use the quadratic formula to solve x2 + 2x - 120 = 0. Think about what other method could also be used to solve this equation. a x = 10, x = 12 b x = -10, x = 12 c x = -12, x = 10

Answer 1

Answer:

x = 10 , -12

Step-by-step explanation:

Solution:-

- The given quadratic equation is to be solved using the quadratic formula. The general form of a quadratic equation is:

                           $ax^2 + bx + c =0$  

Where, [ a , b and c are constants ]

- The quadratic formula is given as:

                       

                           $x = \frac{-b+/-\sqrt{b^2 - 4*a*c} }{2a}$

- The given equation is:

                             $x^2 + 2x - 120 = 0$

Where, a = 1 , b = 2 , c = -120

- Solve using quadratic formula:

                       $x = \frac{-2+/-\sqrt{2^2 - 4*1*(-120)} }{2*1}\\\\x = \frac{-2+/-\sqrt{4 + 480} }{2}\\\\x = \frac{-2+/-(22) }{2}\\\\\\x = 10 , -12$