Originally posted by knptmug at 2005-4-20 09:47 PM:$ L( c5 A& z6 Y+ h: z
set small watermelon: x, middle watermelon y and big watermeton z + q7 W( o' W7 J! y5 N0 p" t* E - U: h) W7 \7 ?/ [) j- Utwo simultaneous equations are set up: 9 O* w! K' v3 k* z8 @0.5x+2y+5z=50 (1) ; Z, Q' t; }* N! w" V' _x+y+z=50 (2)3 I3 m' W: ]$ H7 U8 B) J
Equation(1) means that the total amount paid is equal t ...