Find the solution set of the quadratic equation over the set of complex numbers

-7x^2+12x=10

9/10 divide by -3/15 as a mixed number

Write the sine and cosine values of a, b, respectively, in the figure for (1) and (2) + explanation.

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters