= -36х-2,4у-14у+42х=6х-16,4у=6*(-3,1)-16,4*0,3= -18,6-4,92= -23,52
-24<2a<20
60>-5a>-50
12>-a>-10
-7<a+5<15
-4<8-a<-2
-1/12<1/a<-1/10
-1/4<3/a<3/10
-23<2a+1<21
41>5-3a>-25
<span>sin11x*cos3x-cos11x*sin3x=</span>√<span>3/2
sin(11x-3x)=</span>√3/2
sin8x=√3/2
![8x=(-1)^n* \pi /3+ \pi n, n\in Z\\x=(-1)^n* \pi /24+ \pi n/8, n\in Z](https://tex.z-dn.net/?f=8x%3D%28-1%29%5En%2A+%5Cpi+%2F3%2B+%5Cpi+n%2C+n%5Cin+Z%5C%5Cx%3D%28-1%29%5En%2A+%5Cpi+%2F24%2B+%5Cpi+n%2F8%2C+n%5Cin+Z)