Originally posted by knptmug at 2005-4-20 09:47 PM:1 _1 m! @% \7 h* p5 f
set small watermelon: x, middle watermelon y and big watermeton z7 ]# w- s# _. f* f' [
2 j! E K: e+ J/ @
two simultaneous equations are set up:5 e1 ]; l0 b. |3 W' [& ^# @" V
0.5x+2y+5z=50 (1) n, O- ~! U/ |% |x+y+z=50 (2); P' k5 n0 L* f4 T6 }5 Q9 e) `
Equation(1) means that the total amount paid is equal t ...