a) P_{4} = 4! =1·2·3·4 = 24; б) = 1/40320; b)[tex]C^2_27 = \frac{27!}{2!(27! - 2!)} = 351;
C^2_26 ={26!}{2!(26! - 2!)} =50; 351 - 50 =301;
г) [tex]A^3_10 = \frac{10!}{(10 - 3)!} = 720; [tex]C^3_10 = \frac{10!}{3!(10-3)1} = 120; 720÷120 = ;6
хм,, давно не решал такие)
ну вроде надо:
20*3=60,
360/60=6 человек
= 12/7 - 50/26 : 45/26 = 12/7 - 9/10 = 120-63/70 = 57/70
(t+11)^3 - 4^3 = (t + 11 - 4)((t+11)^2 + 4(t+11) + 16) = (t + 7)(t^2 + 26t + 181)