Answer:
a+c =11
a +3c = 19
a =7 and c = 4
Step-by-step explanation:
Let a = price of one adult
c = price of one child
We know one adult and one child = 11
a+c =11
Mrs smith and 3 children spent 19
a +3c = 19
We have 2 equations and 2 unknowns
a+c =11
a +3c = 19
Multiply the first equation by -1 so we can eliminate a
-a-c=-11
a+3c=19
----------------
2c = 8
Divide by 2
2c/2 = 8/2
c=4
Each child equals 4 dollars
Now we need to find a
a + c= 11
a+4 = 11
Subtract 4 from each side
a+4-4 = 11-4
a = 7
The adult is 7