Step-by-step explanation:
x = number of polio vaccinations.
y = number of measles vaccinations.
in total 60 vaccinations means
x + y = 60
and remembering the doses needed per vaccination we get
4x + 2y = 184
out of the first equation we get
x = 60 - y
and we use that in the second equation
4×(60 - y) + 2y = 184
240 - 4y + 2y = 184
-2y = -56
y = 28
x = 60 - y = 60 - 28 = 32
Dr. Potter gave 32 polio and 28 measles vaccinations.
