Question

Решите уравнения(всё расписать,все действия) :

Answer 1

$4) 6 x^{2} -7x+1=0\\D=49-24=25 \\ \sqrt{D} =5 \\ x_{1} = \frac{7+5}{12} = \frac{12}{12} =1 \\ \\ x_{2} = \frac{7-5}{12} = \frac{2}{12} = \frac{1}{6} \\ \\ 5) x^{2} +2x-15=0 \\ D=4+60=64 \\ \sqrt{D} =8 \\ x_{1} = \frac{-2+8}{2} = \frac{6}{2} =3 \\ \\ x_{2} = \frac{-2-8}{2} =- \frac{10}{2} =-5$

$6) x^{2} -6x-16=0 \\ D=36+64=100 \\ \sqrt{D} =10 \\ x_{1} = \frac{6+10}{2} = \frac{16}{2} =8 \\ \\ x_{2} = \frac{6-10}{2} = \frac{-4}{2} =-2$