求助，代数式化简运算出现相同项不消去 ，很烦恼

In[96]:= Subscript[U, a] =
bcd (Subscript[B, a] + Subscript[RW, ca] + Subscript[RP, da]) + (1 -
b) cd (Subscript[B, a] + Subscript[RW, ca] + Subscript[RP, da]) +
b (1 - c) d (Subscript[B, a] + Subscript[RP, da]) +
bc (1 - d) (Subscript[B, a] + Subscript[RW, ca]) + (1 - b) (1 -
c) d (Subscript[B, a] + Subscript[RP, da]) + (1 - b) c (1 -
d) (Subscript[B, a] + Subscript[RW, ca]) +
b (1 - c) (1 - d) (Subscript[B,
a]) + (1 - b) (1 - c) (1 - d) (Subscript[B, a])
Out[96]= (1 - b) (1 - c) (1 - d) Subscript[B, a] +
b (1 - c) (1 - d) Subscript[B,
a] + (1 - b) (1 - c) d (Subscript[B, a] + Subscript[RP, da]) +
b (1 - c) d (Subscript[B, a] + Subscript[RP, da]) +
bc (1 - d) (Subscript[B, a] + Subscript[RW, ca]) + (1 - b) c (1 -
d) (Subscript[B, a] + Subscript[RW, ca]) +
bcd (Subscript[B, a] + Subscript[RP, da] + Subscript[RW, ca]) + (1 -
b) cd (Subscript[B, a] + Subscript[RP, da] + Subscript[RW, ca])
In[97]:= Simplify[%]
Out[97]= (1 + bc + bcd - b c + cd - b cd - bc d - c d +
b c d) Subscript[B, a] + (bcd + cd - b cd + d - c d) Subscript[RP,
da] + (bc + bcd - bc d - (-1 + b) (c + cd - c d)) Subscript[RW, ca]

新手求助，感谢大佬

你这输入有问题 变量之间相乘要打空格或者* 系统不会认为bc和b*c是同一个参数