Question

Find the discriminant, and determine the number of real solutions. then solve 2x^2+3x-9=0

Answer 1

Discriminant = 
b² - 4ac

3² - 4(2)(- 9)
9 + 72
81

Your equation has two real solutions.

2x² + 3x - 9 = 0
2x² + 6x - 3x - 9 = 0
2x(x + 3) - 3(x + 3) = 0

(2x - 3)(x + 3) = 0

Set each equal to zero:

2x - 3 = 0
2x = 3
x = 3/2

x + 3 = 0
x = - 3

Your two solutions are x = - 3, 3/2