Question

Solve the equation. 2x²-3x-5=0

Answer 1

x1 = -1

x2 = 2.5

Explanation:

2x² - 3x - 5 = 0

x = {-(-3)±√((-3)²-(4*2*-5))} / (2*2)

x = (3±√(9+40)} / 4

x = {3±√49} / 4

x = {3±7} / 4

x1 = {3-7} / 4 = -4/4 = -1

x2 = {3+7} / 4 = 10/4 = 2.5

Check:

x2:

2*2.5² - 3*2.5 - 5 = 0

2"6.25 - 7.5 - 5 = 0

12.5 - 7.5 - 5 = 0

x1:

2*-1² -3*-1 -5 = 0

2*1 +3 - 5 = 0

2 + 3 - 5 = 0