240 days is 4 times the half-life, which means that a sample of 1000 mg will decay to

after 240 days.
I would but my teacher has a ad blocker on and I cant access the attachment :P
Answer:
Scale factor, K = -1/4
Step-by-step explanation:
Dilation of any image changes its size and the shape remains same.
The scale factor is the ratio of dilated image to original image.
Dilation rule: (x, y) → (kx, ky), where k is the scale factor.
It means k = x₂/x₁ or y₂/y₁
K = -5/20 = -1/4 or K = -4/16 = -1/4.
<u>The negative value of scale factor (K) indicates dilations with 180 degree rotation of the dilated image.</u>
Hence the scale factor is K = -1/4.