Sure, here is how I broke it down. The bird is flying a constant X miles per hour with a wind speed of Y miles per hour. So, there are two equations that you use to solve. Here they are:
X+Y=12 X-Y=4
Now, you have to use substitution or elimination to solve (I will use elimination). To use elimination, you simply add both equations together to get:
2X=16 Solve for X by dividing by 2.
X=8. We already established that X is the speed of the bird. Plug X back into either of the equations to find the windspeed.
(8)+Y=12
Subtract 8 from both sides.
Y=4. We already established that Y is the windspeed.
So, the speed of the bird (X) is 8mph and the speed of the wind (Y) is 4mph.
