3 D + 2 d = 32
4 D + 3 d = 44
multiply first by 3, second by 2
9 D + 6 d = 96
8 D + 6 d = 88 subtract
----------------
D = 8
so 3*8 + 2 d = 32
2 d = 8
d = 4
so
2(8) + 1(4) = 20
Three ducks and two ducklings weigh 32 kg. Four ducks and three ducklings weigh 44kg. All ducks weigh the same and all ducklings weigh the same. What is the weight of two ducks and one duckling?
20kgs?
4 answers
Thank You!
omg this is so useful thanks a lot
Why would you multiply it by two or three though?
1 answer