1) RED will be rotated 90° counterclockwise around the origin.
2) The coordinates of R'E'D' will be R'(2, 2); E'(0, 4) and F'(0, 0). The rule for a 90° counterclockwise rotation about the origin is that the coordinates (x, y) are mapped to (-y, x).
3) An isometric transformation is one in which the angles between sides and the distances of each side are preserved between the pre-image and the image. This means the angle measures and side lengths will be the same. Therefore the image will be similar to the pre-image, as the angle measures will be the same and the side lengths will be proportional.
Assuming the envelope consumption is proportional to the number of typists, you have ...
(12 dz)/36 = x/125
125*(12 dz)/36 = x = 41 2/3
An office of 125 typists would use 41 2/3 dozen envelopes per day.
So I’ll do question 3. So normally you see f(x)= something plus x (something like that) you see it as a function of x.
So that notation of f(-1) means the function of -1. Which means you need to sub in -1 for x.
f(x)=-5x+5
f(-1)=-5(-1)+5
Negative times a negative is a positive
f(-1)=5+5
f(-1)=10
30000 is the answer I think