Originally posted by knptmug at 2005-4-20 09:47 PM:% g: h* B& ]5 M' [# a0 S/ n
set small watermelon: x, middle watermelon y and big watermeton z * L, P9 Z1 p* [& a3 |* b e/ A9 e" }( w1 h
two simultaneous equations are set up:# v: M, s+ ?% R$ E
0.5x+2y+5z=50 (1) + t/ d# _/ O0 p R3 x3 P8 ax+y+z=50 (2) 2 s) s) q# p' a$ cEquation(1) means that the total amount paid is equal t ...
( k) K* n! v9 ~, Q* b B3 v* y:lol::lol:( G! G$ P- u! r3 P7 _" s
楼主的标题就是给你写的!8 r' `+ J3 I* R% U8 r* k t
你看看我们智力超群的同学们回答的都多好啊!