What’s the slope I also have to simplify it

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)

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

What happens to the area as the sliders are adjusted? what do you think the formula for the area of a triangle is divided by 2?