here, 7 cellphone,9 Tv, 12airconditioners = 8723
5 cellphone,7 Tv, 12airconditioners = 6523
or, 7,9,12=8723
-5,7,9=6523
______________
2,2,3=2191
then,
to make 4 cellphone , 4 tv set , 6 air conditioners add twice the answer ,
2,2,3=2191
+2,2,3=2191
____________
4,4,6=4382
hence,
the price of 4 cellphone , 4 tv set and 6 air conditioners is 4382 #
solved by
pratik