若a2=b3=c5(abc≠0),则a+b+ca−b+c=______.
问题描述:
若
=a 2
=b 3
(abc≠0),则c 5
=______. a+b+c a−b+c
答
设
=a 2
=b 3
=k,那么a=2k,b=3k,c=5k,c 5
∴
=a+b+c a−b+c
=2k+3k+5k 2k−3k+5k
.5 2
故答案是:
.5 2
答案解析:先设
=a 2
=b 3
=k,可得a=2k,b=3k,c=5k,再把a、b、c的值都代入所求式子计算即可.c 5
考试点:比例的性质.
知识点:本题考查了比例的性质.解题的关键是先假设
=a 2
=b 3
=k,得出a=2k,b=3k,c=5k,降低计算难度.c 5