2x^2-5x-3=0
D=b^2-4ac
D=25-4*2*(-3)= 25+24=√49=7
x1,2= -b+-√d: 2a
x1= 5-7: 2*2= -0,5
x2= 5+7:2*2= 7
-3tga+3tga-tga=-tga=-0.05
2) -8/x=-2x
-2x^2 = -8
x^2 = 4
x=+/- 2
y1=-8/2=-4
y2=-8/-2=4
Ответ (2:-4) (-2:4)
4) 6/х+1 = х+2
6/х =х+1
х^2+x =6
x^2+x-6+0
x1=3; x2=-2
y1=3+2 = 5: y2=-2+2+0
Ответ:(3:5) (-2:0)