A. 4 yards hope this helped!!!
So you already have the formula for calculating the dosage for child with: C = a/(a+12)x 180 ml Not sure why you have double brackets
variables are: a = child's age, so everywhere you have an "a" replace it with the age of child.
Example: 5 year old child
C = 5/(5+12)*180= 5/(17)*180 = 5/3060 = .0016 ml or milligrams
Substitute
4x+2=x-4
Then solve
3x=-6
x=-2
Substitute answer into an equation to find y
y=-2-4
y=-6
So you solution is:
(-2,-6)
No image shown but just remember that percentage is out of 100
0.03 is 3%
Answer: is in the picture