Answer:
From the graph: we have the coordinates of RST i.e,
R = (2,1) , S = (2,-2) , T = (-1,-2)
Also, it is given the scale factor 
and center of dilation C (1,-1)
The mapping rule for the center of dilation applied for the triangle as shown below:
or
or
Now,
for R = (2,1)
the image R' = 
or
⇒ R' = 
For S = (2, -2) ,
the image S'= 
or
⇒ S' = 
and For T = (-1, -2)
The image T' = 
or
⇒ T' = 
Now, label the image of RST on the graph as shown below in the attachment:
The half-life of the radioactive substance is 67.95 hours.
25 pounds would be a better deal
So to set up the equation we have:
<span><span><span>4M</span><span>4+M</span></span>=<span>127</span></span>
<span>28M=12(4+M)</span>
<span>28M=48+12M</span>
<span>28K−12M=48</span>
<span>(28−12)M=48</span>
<span>16K=48</span>
<span>M=<span>4816</span></span>
<span>M=3</span>
So Marna can clean the chimney alone in 3 hours
We see here in the diagram that the base is a. We know this because the height is perpendicular to it. We also know the height is bsin(C) which, when replace h for bsin(C) and a for the base, we get A=absin(C), which is the second option.
