（x-1）5次方+5（x-1）4次方+10（x-1）3次方+10（x-1）2次方+5（x-1)等于A.x5次方 B.x5次方 -1 C.x5次方 +1 D.(x-1)5次方 -1

（x-1）5次方+5（x-1）4次方+10（x-1）3次方+10（x-1）2次方+5（x-1)等于A.x5次方 B.x5次方 -1 C.x5次方 +1 D.(x-1)5次方 -1
（x-1）5次方+5（x-1）4次方+10（x-1）3次方+10（x-1）2次方+5（x-1)等于
A.x5次方 B.x5次方 -1 C.x5次方 +1 D.(x-1)5次方 -1

（x-1）5次方+5（x-1）4次方+10（x-1）3次方+10（x-1）2次方+5（x-1)等于A.x5次方 B.x5次方 -1 C.x5次方 +1 D.(x-1)5次方 -1
选择B
(a+b)^5=a^5+5a^4*b+10a^3*b^2+10a^2*b^3+5a*b^4+b^5
令a=x-1,b=1
则,[(x-1)+1]^5=(x-1)^5+5(x-1)^4+10(x-1)^3+10(x-1)^2+5(x-1)+1
即,(x-1)^5+5(x-1)^4+10(x-1)^3+10(x-1)^2+5(x-1)=[(x-1)+1]^5-1=x^5-1

(1+x-1)^5,A

xˆ5―1