X`2-2=|x|
2-x`2=x or x`2-2=x
x(x+1)=2 x(x-1)=2
x=-2 x=-1
x=1 x=2
5! = 1*2*3*4*5=120
6! = 1*2*3*4*5*6=720
<span>5!+6!+7! / 8!-7! = 5!(1+6+6*7)/7!(8-1)=(7+42)/6*7*7=49/(42*7)=1/6
</span>
<span>|x|=5
</span>х=5 или х=-5
<span>|x|=10
</span>х=10 или х=-10
1) cos105cos5 + sin105cos85 = cos105cos(90-85) + sin105cos85 =
=cos105sin85 + sin105cos85 = sin(105+85) = sin190
2)sin195cos5 + cos195sin185 = sin195cos5 + cos195sin(180+5) =
=sin195cos5 - cos195sin5 = sin(195-5) = sin190
sin190/sin190 = 1
X²/(4+x)=16/(4+x)
x²/(4+x)-16/(4+x)=0
x²-16/(4+x)=0
x²-16=0
4+x≠0
x²=16
x≠-4
x=4
x≠-4
Ответ: х=4
x/(20-x)=1/x
x/(20-x)-1/x=0
x²-20+x/(x(20-x)=0
x²+x-20=0
x≠0
20-x≠0
x₁=5
x₂=-4
x≠0
x≠-20