Multiplicar por '12'

1/4 x² + 1/3 x + 1/12 = 0 (12)

12/4 x² + 12/3 x + 12/12 = '0'

3x² + 4x + 1 ='0'

a= 3; b =4; c = '1'

∆= b² - 4ac

∆= 4² - 4.3.1

∆ = 16-12

∆= '4'

X = (-b +/- √∆)/2a4

x = (-4+/- √4/2.3

X = (-4+/-2)/'6'

x' = (-4-2)/'6'= -6/6 = '-1'

X" = (-4+2)/6'= -2/6= '-1/3'