Alexanderyin
幼苗
共回答了23个问题采纳率:95.7% 举报
设2007乘以a的平方 = 2008乘以b的平方= 2009乘以c的平方= 2010乘以d的平方=k
2007a=k/a,2008b=k/b,2009c=k/c,2010d=k/d
√(2007a+2008b+2009c+2010c)=√k(1/a+1/b+1/c+1/d)=√k
∵a=√(k/2007),b=√(k/2008),c=√﹙k/2009﹚,d=√(k/2010)
1/a+1/b+1/c+1/d = 1
∴√(1/k)(√2007+√2008+√2009+√2010)=1
∴√k=√2007+√2008+√2009+√2010
即√(2007a+2008b+2009c+2010c)=√k=√2007+√2008+√2009+√2010
1年前
2