Х+2х=3600
3х=3600
х=3600:3
х=1200
Проверка:
1200+2·1200=3600
1200+2400=3600
3600=3600
1) x:72=10 x=10*72 x=720; 720:72=10 2) 600:x=100 x=600:100 x=6; 600:6=100 3) x*10=350 x=350:10 x=35; 35*10=350 4) 540:x=54 x=540:54 x=10; 540:10=54
8900*456=4058400
Вроде так.
6994 . ..........................
1)S=3R²√3/2=60,75π⇒R²=60,75π:3√3/2π=243/4*2/3√3=27√3/2⇒
⇒R=3/2*
![\sqrt[4]{108}](https://tex.z-dn.net/?f=+%5Csqrt%5B4%5D%7B108%7D+)
2)x={-1;0;1;2;3;4;5;6;7}
3)tgx+1/tgx=-2
tg²x+2tgx+1=0
(tgx+1)²=0
tgx=-1
x=-π/4+πn