It's a scale factor of 3. the way you find out is by counting from the center point to an edge point on the orignal. then do the same on the scales one. now divide the scaled one by the orignal and bam you get the answer
        
             
        
        
        
$18.11 because 20.75/x=100/15
<span>(120.75/x)*x=(100/15)*x       - </span>we multiply both sides of the equation by x
<span>120.75=6.6666666666667*x       - </span>we divide both sides of the equation by (6.6666666666667) to get x
<span>120.75/6.6666666666667=x </span>
<span>18.1125=x </span>
<span>x=18.1125</span>
        
             
        
        
        
Answer:
She will get <u>80mg</u> of dextromethorphan and <u>800mg</u> of guaifenesin. And the bottle last for <u>6 days</u> approximately.
Step-by-step explanation:
Given that the Robitussin DM contains dextromethorphan 10mg/5mL and gualfenesin 100mg/5mL. And we are also given that Mrs Smith took four doses and each dose is 2 teaspoons=2X5=10mL.
So, four doses=4X10=40mL.
So, dextromethorphan in 4 doses is = 
And Guaifenesin in 4 doses is =  
 
Dosage of medicine daily she has to take=40mL and the bottle contains 237 mL. Hence the number of days bottle last =  ≈6 days approximately.
≈6 days approximately.
 
        
             
        
        
        
where's the rest of question so I can help?