Question 551058
let there be x birds on tree 1
y birds on tree2

one flies from tree 1

x-1= y+1
x-y=2............1

One flies from tree2

x+1 = 2(y-1)
x+1 =2y-2
x-2y=-3...............2

multiply equation (1) by -1
-x+y =-2
add to (2)
x-2y=-3



-y = -5
y=5

plug y =5 in any equation
we get x=7

tree 1 has 7 birds
& tree 2 has 5 birds