Question

How do I Solve x2 + 7x -20 = 0 using a quadratic formula?

Answer 1

We first must determine the coefficients

a = 1

b = 7

c = -20

Then we use the quadratic formula:

x = [-7 +- sqr root (7^2 - 4 * 1 * -20)] / 2 * 1

x = [-7 +- sqr root (129)] / 2

x1 = 4.3578166916 / 2

x1 = 2.1789083458

x2 = -18.3578166916 / 2

x2 = -9.1789083458

Explanation: