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

x = 10 , -12

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 = (-b+/-√(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 = (-2+/-√(2^2 - 4*1*(-120)) )/(2*1)\\\\x = (-2+/-√(4 + 480) )/(2)\\\\x = (-2+/-(22) )/(2)\\\\\\x = 10 , -12`