4\x-1=x\5. xне равен 1
20=x(x-1)
20-x9x-1)=0
20-x^2+x=0
x^2-x-20=0
D=(-1)^2-4*1*(-20)=81
x1=(1-9)/2=-4
x2=1+9/2=5
x-9/x=0. x не равно 0
x-9=0
x=9
25/y-y=0. y не рано 0
(25-y^2)/y=0
25-y^2=0
y^2=25
y1=5
y2=-5
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.
sin^2 105 градусов - cos^2 105 градусов=1-2cos^2 105 градусов = -(2cos^2 105 градусов -1) = -cos210 градусов
sin^2 105 градусов=1-cos^2 150 градусов
3х-8 / 2 = -1
3х-8 = -2
3х = -2+8
3х = 6
х = 6:3
х = 2