Help me out, thanks.

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

Is a positive integer raised to a negative power always positive

Abird on top of a 200 ft bridge tower sees a man standing on the lower part of the bridge (which is 50 ft above the ground). the angle of depression from the bird is 26 ̊. how far is the man from the base of the bridge tower? with explanation and pictures .