How much are these coins worth?

Solve each quadratic equation by factoring and using the zero product property. 10x + 6 = -2x^2 -2

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?

Y= 4x + 3 y = - 1 4 x - 5 what is the best description for the lines represented by the equations?