1、最快的口算方法是:
思路:假设鸡兔训练有素,一声口哨,鸡独立,兔站立,脚少了一半,为78÷2=39条腿.
再吹一声口哨,鸡一屁股坐到地上,兔子一只脚站立,为39-24=15条腿即兔子有15只.
鸡有 24-9=15(只)
2、标准二元一次方程组解法:
设鸡X只,兔Y只.
列方程:X+Y=24 ①
2X+4Y=78 ②
②-①×2得2Y=30,Y=15(只)
X=24-15=9(只)
答:鸡有9只,兔有15只.
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