獵人帶狗追捕，兔子剛跑80步，獵狗去追兔子，已知獵狗跑2步的時(shí)間兔子跑3步，獵狗跑4步的距離與兔子跑7步的距離相等。那么獵狗跑多少步可以捕獲這只兔子？
距離80步
2a/x = 3b/y
-> 2ay = 3bx
-> x = 2ay/3b
4*a = 7*b
->a = 7b/4
帶入x = 2ay/3b
x = 2*7by/12b
x = 7y/6
?
b = 4a/7
(n*a - 80*b)/y = n*a/x
n*a*x - 80*b*x = n*a*y
n*a*(x-y) = 80*b*x
n = 80*b*x
?? ------------
??? a*(x-y)
?? = ?80 *4a/7* 7y/6
?? ----------------
?? a* (7y/6 - y)
?= 80*4/7 *7y/6
?---------------
?1y/6
?= 80*4=320
?
?
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