X-5 = x²-25
x-5-x²+25 = 0
-x²+x+20 = 0 I *(-1)
x²-x-20 = 0
D=√1+80=√81=9.
1+9 10
x₁ = _____ = ____ = 5.
2 2
1-9 - 8
x₂ = _____ = ____ = - 4.
2 2
Ответ : - 4 ; 5.
7x - x - 3 = 6x - 3
7x - x - 6x = -3 + 3
0 = 0
1-1
2-1
3-1
4-не знаю чет
5-1
Cos120= -1/2
sin315= -1/2
cos120+sin315= -1/2+(-1/2)= -1/2 - 1/2= -2/2= -1