That's an awfully broad question. Could you not be more specific?
A basic example: Suppose you are told that sin theta = 1/2. Solving this equation would require finding the measure of the angle theta. In this case the answer would be "30 degrees," or "pi/6 radians."
Follow the rules of PEMDAS:
42/(15-8)
42/7
6
Step-by-step explanation:
use the midpoint formula

substitute into the midpoint formula

solve the above
(

so the x coordinate if your midpoint is 3
the y coordinate of your midpoint is 1
(3;1)