6 2/3 * 1/8 = 20/3 * 1/8 = 5/6 часа отводится на перемены
<span>5/6 часа = 50 минут</span>
6 ----------------------------------------------------------
А 15*6/18*19+6=101
б (88-19)/23*15+55=100
в ((100-19)/3 +23)*4=200
г (80-16)/8*11+22=110
д (60-11)/7*15-25=80
(sina+cosa)/(sina-cosa)=(sina/cosa + 1)/(sina/cosa - 1) = (tga+1)/(tga-1) = (3/5+ 1)/(3/5-1) = (0.6+1)/(0.6-1)=1.6/-0.4=16/-4=-4