解答
展开 (0.25+q)7
解答
163841+40967q+20.041015625q2+60.8203125q3+63.28125q4+22.625q5+47q6+q7
求解步骤
(0.25+q)7
使用二项式定理: (a+b)n=i=0∑n(in)a(n−i)bia=0.25,b=q
=i=0∑7(i7)⋅0.25(7−i)qi
展开求和
=0!(7−0)!7!⋅0.257q0+1!(7−1)!7!⋅0.256q1+2!(7−2)!7!⋅0.255q2+3!(7−3)!7!⋅0.254q3+4!(7−4)!7!⋅0.253q4+5!(7−5)!7!⋅0.252q5+6!(7−6)!7!⋅0.251q6+7!(7−7)!7!⋅0.250q7
化简 0!(7−0)!7!⋅0.257q0:0.00006…
化简 1!(7−1)!7!⋅0.256q1:0.00170…q
化简 2!(7−2)!7!⋅0.255q2:20.041015625q2
化简 3!(7−3)!7!⋅0.254q3:60.8203125q3
化简 4!(7−4)!7!⋅0.253q4:63.28125q4
化简 5!(7−5)!7!⋅0.252q5:22.625q5
化简 6!(7−6)!7!⋅0.251q6:1.75q6
化简 7!(7−7)!7!⋅0.250q7:q7
=0.00006…+0.00170…q+20.041015625q2+60.8203125q3+63.28125q4+22.625q5+1.75q6+q7
化简 0.00006…+0.00170…q+20.041015625q2+60.8203125q3+63.28125q4+22.625q5+1.75q6+q7:163841+40967q+20.041015625q2+60.8203125q3+63.28125q4+22.625q5+47q6+q7
=163841+40967q+20.041015625q2+60.8203125q3+63.28125q4+22.625q5+47q6+q7