Originally posted by knptmug at 2005-4-20 09:47 PM:4 ~' g# q" A( f) d, N, Y
set small watermelon: x, middle watermelon y and big watermeton z) ~" R" N8 J: g3 T6 m/ k
7 `; X" b! _6 P# a" G* U
two simultaneous equations are set up: G6 ]; i. E4 h0.5x+2y+5z=50 (1)6 a. ~- a4 p: K% M; m/ m' t9 Q
x+y+z=50 (2)9 ^6 x, _2 J% ~
Equation(1) means that the total amount paid is equal t ...