4) 18 = 10,6 + 3,7p
3,7p = 7,4
p = 2
5) sin 930^o = sin 210^o = sin (3pi/2 - 60^o) = -cos 60^o = - 1/2
1)(28/5-4/3):(91/12-9/4)*1.25
(84/15-20/15):(91/12-27/12)*1.25
64/15:64/12*1.25
64/15*12/64*5/4
15/12*5/4
5/4*5/4=25/16
14/25 + 3/2 = 28/50 + 75/50 = 103/50 = 2 целых 3/50
или
14/25 + 3/2 = 0,56 + 1,5 = 2,06