Решите уравнения: а)x^2+6x+5=0 б)2x^2-5x+3=0 в)2x^2-7x-4=0

[latex]x^2+6x+5=0\\ D=36-20=16; \sqrt{D} =4\\ x_{1/2}= \frac{-6\pm4}{2}\\\\ x_1= -\frac{10}{2}=-5\\\\ x_2=- \frac{2}{2}=-1\\\\\\ 2x^2-5x+3=0\\ D=25-24=1; \sqrt{D} =1\\ x_{1/2}= \frac{5\pm1}{4}\\\\ x_1= \frac{4}{4} =1\\\\ x_2= \frac{6}{4} = \frac{3}{2}\\\\\\ 2x^2-7x-4=0\\ D=49+32=81; \sqrt{D}=9\\ x_{1/2}= \frac{7\pm9}{4}\\\\ x_1=- \frac{2}{4}=- \frac{1}{2}\\\\ x_2= \frac{16}{4}=4 [/latex]

a) D=36-20=16=4² x1=(-6+4)/2= -1 x2=(-6-4)/2= -5 b) D=25-24=1 x1=(5+1)/4=6/4=3/2=1.5 x2=(5-1)/4=1 v) D=49+32=81=9² x1=(7+9)/4=4 x2=(7-9)/4= -2/4=-1/2= -0.5