已知一列数a1,a2a3a4a5a6a7且a1=1,a7=729,a1/a2=a2/a3=a3/a4=a4/a5=a5/
已知一列数a1,a2a3a4a5a6a7且a1=1,a7=729,a1/a2=a2/a3=a3/a4=a4/a5=a5/
已知一列数a1,a2,a3,a4,a5,a6,a7,且a1=1,a7=729,a1/a2=a2/a3=a3/a4=a4/
已知a1,a2,a3,a4,a5是5个整数且a1=1,a5=6,求证a2-a1,a3-a2,a4-a3,a5-a4中至少
等差数列a3+a4+a5=12,求a1+a2+a7
A1+A3+A5+A7=4,求A2+A4+A6
已知a1、a2、a3、a4、a5是非负实数,且a1+a2+a3+a4+a5=120,X表示a1+a2、a2+a3、a3+
已知a1、a2、a3、a4、a5为非负有理数,且M=(a1+a2+a3+a4)(a2+a3+a4+a5),N=(a1+a
已知集合A={a1,a2,a3,a4,a5,a6,a7},A并上B={a1,a2,a3,a4,a5,a6,a7,.,a1
等差数列中a1+a2+a3+a4+a5=3,a1*a1+a2*a2+a3*a3+a4*a4+a5*a5=12求a1-a2
已知集合A={a1,a2,a3,a4,a5,a6,a7},A∪B={a1,a2,a3,a4,a5,a6,a7.,a100
已知集合AUBUC={a1,a2,a3,a4,a5},
设A=(a1,a2,a3,a4,a5),a1,a3,a5线性无关,a2=3a1-a3-a5,a4=2a1+a3+6a5,