3m-2n=9
<span>5m+n=15 |*2
3m-2n=9
10m+2n=30
13m= 39
m= 3
n= 0
Ответ: (3;0)</span>
<span>6sin П/6-2cos0+tg^2 П/3=6*1/2-2*1+(<span>√3)^2=3-2+3=4</span></span>
Cos x= п/3, т.к. п/3€[0;п]
х= 1/2
(3х-1)^2+(3х-1)*(3х+1)=(3х-1)^2+9х^2-1=(3х)^2-2*3х*1+1^2+9х^2-1=9х^2-2*3х+9х^2=18х^2-2*3х=18х^2-6х.