1) 小麗 is x 歲
(x-8)4=x+12-8
4x-32=x+4
4x=x+36
3x=36
x=12
So 哥哥=12+12=24歲,小麗=12歲
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2) 第一小組 has x 人
(x)+(x+2)+(x+x+2-20)=180
4x-16=180
4x=176
x=44
So 第一小組 has 44 人
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I hope I can help you
2006-12-09 12:01:52 補充:
Sorry,2)4x=176 is wrong,it should be 4x=196 x=49 So 第一小組 has 49 人I am sorry about my mistake