Can someone please help me on mymath

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?

Pentagon abcde is dilated according to the rule do,3(x, y) to create the image pentagon a'b'c'd'e', which is shown on the graph. what are the coordinates of point a of the pre-image? a) (-1, 1)b) (-1, 2)c) (-9, 6)d) (-9, 18)

If you were constructing a triangular frame, and you had wood in the length of 4 inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood?