If in triangle ABC, angle c=90 degrees then sin(A+B)=?

Use the quadratic formula to solve 5x=6x^2-3,what are the values of x?

What are the solutions of the system? solve by graphing. y = x^2 + 3x + 2 y = 2x + 2

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.