Can someone help to fine goths slope, y intercept and equation

The vertices of a rectangle are given in the columns of the matrix . if is found to perform a transformation, what are the coordinates of the transformed rectangle? (0, 0), (0, –3), (–3, –3), (–3, 0) (0, 0), (0, 3), (3, 3), (3, 0) (0, 0), (0, 3), (–3, –3), (–3, 0) (0, 0), (0, 3), (–3, 3), (–3, 0)

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

What values of x satisfy the inequality x^2-9x< 0? how is your answer shown on the graph?