john_xu2002
春芽
共回答了18个问题采纳率:83.3% 举报
所谓的对白1:
∵|2a-b+1|+(3a+3/2b)²=0
且|2a-b+1|≥0,(3a+3/2b)²≥0
∴2a-b+1=0,3a+3/2b=0
解得a=-1/4,b=1/2
∴[b²/(a+b)]÷[a/(a-b)-1]×[a-a²/(a+b)]
=[b²/(a+b)]÷[a/(a-b)-(a-b)/(a-b)]×[a(a+b)/(a+b)-a²/(a+b)]
=[b²/(a+b)]÷[b/(a-b)]×[ab/(a+b)]
=[b²/(a+b)]×[(a-b)/b]×[ab/(a+b)]
=[b²×(a-b)×ab]/[(a+b)²×b]
=[1/4×(-3/4)×(-1/8)]/[(1/16)×(1/2)]
=(3/128)/(1/32)
=(3/128)×32
=3/4
1年前
4