UC知道a farmer has some pigs and some ducks.there are 9 headsand 26 feet. 有猪多少
来源：百度知道 编辑：UC知道 时间：2024/06/20 23:25:48
四
设猪为x只,鸭y只
猪和鸭的头一共九个所以
x+y=9
猪四只脚鸭两只脚，一共26只脚，所以
4x+2y=26
解方程组得x=4,y=5
所以猪4只，鸭5只
猪有4只 鸭有5只
有四头猪和五只羊...
列2个算式验算..
4×4+2×5=26(脚)
4+5=9(头)
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