6sin40°sin50°/cos10°​

Объяснение:

6*sin40°*sin50°/cos10°=6*sin50°*sin40°/cos10°=

=6*(1/2)*((cos(50°-40°)-cos(50°+cos40°))/cos10°=

=3*(cos10°-cos90°)/cos10°=3*(cos10°-0)/cos10°=3*cos10°/cos10°=3.

a)   p(a)=m/n

m=5

n=7+5=12

p(a)=5/12

б)   m=c 2 из 5 =5! /(2! 3! )=10

n= c 2 bиз 12 = 12! /(2! 10! ) =66

p(a)=10/66=5/33