Originally posted by knptmug at 2005-4-20 09:47 PM:& V$ O9 i' z+ J% Y5 X
set small watermelon: x, middle watermelon y and big watermeton z ( k+ P1 {% B' t0 |/ D5 D! ]/ s+ T0 D+ i8 Q. m2 W
two simultaneous equations are set up:! a! {5 K: Q- M. R: U6 R$ i! M' y
0.5x+2y+5z=50 (1); P5 }1 U; [ X/ k& M
x+y+z=50 (2)9 l7 j; X- k0 k7 T5 H# S, C7 B
Equation(1) means that the total amount paid is equal t ...