5(m+n)^2/(m-n)*(m+n)=5*(m+n)/(m-n)
120/168 делим на 8 = 15/21
720/640 делим на 80 = 9/8, выделяем целую часть=1,1/8
1) cos135°=cos(90°+45°)=-sin45<span>°= -</span>√2/2
2) sin(8π/3)=sin(3π -π/3)=sin(π/3)=√3/2
3) tg(7π/3)=tg(2π + π/3)=tg(π/3)=√3
4) cos(2 * π/8) = cos(π/4)=√2/2