(Assignment, pleass help >.<. "From two points 100 feet apart in a straight line to the base of tree,

From two points 100 feet apart in a straight line to the base of tree, the angles of elevation to the top of the tree is 38 degrees and 53 degrees respectively. Find the height of the tree.

Let y be the height of the tree.
Let x be the distance from the tree to the point where angle of elevation is 53 degrees. Obviously, the point where angle of elevation is 53 degrees is closer to the tree.

Y/x=tan53
Y/100+x=tan38

Y/tan53=x
Y/tan38=100+x
(y/tan38)-100=y/tan53

-100=(-y/tan38)+(y/tan53)
-100=(y*-tan53+y*tan38)/(tan53*tan38)
-100(tan53)(tan38)=(y*-tan53+y*tan38)

-100(tan53)(tan38)=y(-tan53+tan38)
(-100(tan53)(tan38))/(-tan53+tan38)=y

Y=189.970864 feet