Х+у=5
3х-2у+z=6
x-5y+3z=-4
из 1
x=5-y
поставим на 2 и 3
3(5-y)-2y+z=6
5-y-5y+3z=-4
15-3y-2y+z=6
5-6y+3z=-4
-5y+z=-9
-6y+3z=-4
z=-9+5y
-6y+3(-9+5y)=-4
-6-27+15y=-4
15y=30
y=2
z=-9+5*2=1
x=5-2=3
ответ:(3;2;1)
15x² -11x =0
x(15x -11) =0
x =0
15x -11 =0
15x =11
x =11/15
ответ: x =0; x =11/15