what is the answer

Hallo anonymous!

 

solve 3x^2-8x-11=0

 

3 x² - 8 x - 11 = 0                    [ / 3

x² (- 8 / 3) x (- 11 / 3) = 0

p = - 8 / 3      q = - 11 / 3

x(1;2) = - p / 2 ±√ ((p / 2)² - q)

x(1;2) = 4 / 3 ±√ ((4 / 3)² + 11 / 3)

x(1;2) = 4 / 3 ±√ (16 / 9 + 33 / 9) = 4 / 3 ±√ (49 /9) = 4 / 3 ± 7 / 3

x1 = 11/3 = 3  2/3

x2 = - 3/3 = - 1

 

x1 = 3 2/3

x2 = - 1

 

test:

3 x² - 8 x - 11 = 0

3*(11/3)²-8*(11/3)-11=0

0=0     okey

 

3*(-1)²-8*(-1)-11=0

0=0     okey

 

:- )