All triangles have angles that add up to 180, so we can take the top triangle, which has angles 14, 45, and x, and say they add up to 180, so 180-14-45=x and x = 121. For E, all angles that look like that and have opposite angles, then these opposites are equal, so both sides of E are 121. then we use the bottom triangle to solve for D with the fact that all triangles' angles add to 180 again. 180-27-121 = D, so D=32
The first step would be to add 40 to both sides of the equation, you can use multiple methods to solve from there, but I recommend 'completing the square' since your b value is equal to zero :)
