I think there is a little error in your question. I guess You mean 60 vaccinations instead of 606060. I solved using 60 vaccinations.
Answer:Dr. Potter gave 32 polio vaccines and 28 measles vaccinations that year.
Explanation:
STEP 1
Let number of polio vaccines be x
and number of measles vaccine be y
such that
total does of 60 vaccinations be expressed as
x+y = 60---- equation 1
And number of doses for both vaccine to total 184 doses taken be expressed as
4x + 2y= 184 ---- equation 2
Step 2--- solving
x+y = 60---- equation 1
4x + 2y= 184 ---- equation 2
Making x the subject of formula in equation 1 and substituting it in equation 2
x= 60-y
4(60-y) +2y- 184
240-4y+2y=184
240-184= 4y-3y
56= 2y
y= 58/2 = 28
To get x , put the value of y=28 in equation 1 and solve
x+y=60
x=60-28
x=32
Therefore Dr. Potter gave 32 polio vaccines and 28 measles vaccinations that year.