3x в квадрате -x-4=0

[latex] 3x^{2} - x - 4=0 \\ D= b^{2} -4ac= 1^{2} - 4 *3 *(-4)= 1+ 48 = 49 \\ \sqrt{D} = \sqrt{49} =7 \\ x1= \frac{-b+ \sqrt{D} }{2a} = \frac{1+7}{6} = \frac{8}{6} = \frac{4}{3} = 1 \frac{1}{3} \\ x2= \frac{-b- \sqrt{D} }{2a} = \frac{1-7}{6} = \frac{-6}{6} = -1[/latex] Ответ: [latex]-1; 1 \frac{1}{3} [/latex]