Solve for c. i bought three boxes of"end of the world"cards at monastiraki flea market. i used 54 and had 9 cards leftover. how many were in each box?

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?

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

(-y to the power of 2 - 4y- to the power of 2 -6 y +3)