设矩阵A= (3,-2) ,B= 2 4 https:/img.zuoyebang.cc/zyb_7142fe6d884b795b75323081826723ec.jpg,C= 1 -2 3-|||-1 3-|||--4 5 -6，则下列矩阵运算中有意义的是A.CBB.ABCC.BACD.CBA

https:/img.zuoyebang.cc/zyb_7951f03ce916a2297d2b38782b6a2474.jpg+(a)^2-|||-https

https:/img.zuoyebang.cc/zyb_c0fbf0d3ab9a0b30a20e47b6f2b25ba5.jpg-a-|||-C.α^2 D.

,-112 ;-|||-(2) n=3 https:/img.zuoyebang.cc/zyb_7ce6c926494ee9526579fc5c1b7474b4

. https:/img.zuoyebang.cc/zyb_59b3de1062e243c0b1e32e8058920d73.jpg+({x)_(n)}^2

... . 1-|||-1 https:/img.zuoyebang.cc/zyb_a148ede5fabdd95c53fd3b87a9e6b9b0.jpg+(

SiO 2 M2.-|||-S i n 3-|||-A /4n2, 明纹-|||-B /4n2, 暗纹-|||-C /4n2, 明纹-|||-D https:/

(13)(2010年,一)设总体X的分布为:-|||-X 1 2 3-|||-p https:/img.zuoyebang.cc/zyb_2a76612f050

4-|||-https:/img.zuoyebang.cc/zyb_218762fe585dbabaa8e3f46957a71dcd.jpg 0 .-1 2-|

(2)已知 (A)=1/2, (B)=1/3, (C)=1/5, (AB)=1/10, (AC)=1/15, P(BC)=-|||-https:/img.zuo

-dfrac (2)({x)^2} .-|||-C 2x+3 ;-|||-D https:/img.zuoyebang.cc/zyb_c1dbf8c08bc60