75\%=0,75
165/0,75=220
<u><span><em>Ответ: 220 человек</em></span></u>
У(х^2-1) + 3(х^2-1) = (у+3)*(х^2-1)
х^2 - х в квадрате
..............................................
<span>4*sin10*sin 50*sin70=4sin(90-80)sin(90-40)sin(90-20)=4cos80cos40cos20=4cos80cos40cos20sin20/sin20=2cos80cos40sin40/sin20=sin160/2sin20=sin(180-20)/2sin20=sin20/2sin20=1/2</span>
<span>|3x-4y-2|+|x-5y+3| = 0</span>
<span>3x-4y-2=0</span>
<span>x-5y+3=0 (в виде системы)</span>
<span>х=5у-3</span>
<span>3(5у-3)-4у-2=0</span>
<span>15у-9-4у-2=0</span>
<span>11у=11</span>
<span>у=1</span>
<span>х=5у-3</span>
х=2
ответ: min=0; (2;1)