1. (13/18)*(9/26)=0.25
2. 4.625-0.25=4.375
3. 2 1/4=9/4
4. 9/4=2.25
5. 4.375:2.25=(35/18)
6. 2 1/2=5/2
7. 5/2=2.5
8. 2.5:1.25=2
9. 6 3/4=27/4
10. 27/4=6.75
11. 2:6.75=(8/27)
12. (35/18)+(8/27)=(121/5413. 1 53/68=121/68)
13. 1 53/68=121/68
14. (121/54):(121/68)=(34/27)
этовыражение 3. тк 9 делить на з =3
1/2sinα+cos(π/6+α)=sinα/2+cos(π/6)cos(α)-sin(π/6)sin(α)=sinα/2+sqrt3/2*cos(α)-1/2*sin(α)=sinα/2+(sqrt3*cos(α))/2-sin(α)/2=(sqrt3*cos(α))/2