Solve the inequality for u.
-18<-2u

The rows and columns of lattice points in a three-by-three square array are evenly spaced one unit apart. how many distinct triangles with at least one side of length 2 units can be drawn using three lattice points for the vertices?

Figure abcd is a parallelogram. if point c lies on the line x = 2, what is the y-value of point c?

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?