2X3二1X6可以改写成比例为1:2二3:6()对还是错
1x2+2x4+3x6+4x8 ------------------------------- 2x3+4x6+6x9+
(1x2+2x4+3x6+4x8)/(2x3+4x6+6x9+8x12)
2个3相乘.可以写成乘法算式2x3.对还是错
1x1-2x2+3x3-4x4+5x5-6x6.-100x100+101x101
(2013•闸北区二模)(1+2x)3(1-x)4展开式中x6的系数为______.
宝马的 1 3 5 6 7 x3 x5 x6...
)设X服从N(0,1),(X1,X2,X3,X4,X5,X6)为来自总体X的简单随机样本,Y=(X1+X2+X3+)^2
把3×3.5=21×2分之1改写成比例.(至少写出2个)
1x2/1+2x3/1+3x4/1+4x5/1+5x6/1+6x7/1
1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+1/6x7
(2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==?
84÷63X3 1X5.3+2.1X6.2-2.1X1.5