Question

X^2 + x - 20 = 0
If z is a solution of the equation above and z> 0, what is the value of z?

Answer 1

z = 5

Explanation:

x^2 + x - 20 = 0

Two numbers that multiply to get 20 are 5 and 4

(x + 5)(x - 4) = 0

Now we can check this equation:

x * x = x^2

x * -4 = -4x

5 * x = 5x

5 * -4 = -20

x^2 - 4x + 5x - 20 = 0

x^2 + x - 20 = 0

The solutions to this equation are 5 and -4, but since z is more than 0, z is 5