Children : 144
Adults : 51
Step-by-step explanation
Step 1
Set the equations
let
x represents the number of children
y represents the number of adults
charge per child:8
charge per adult:11
total people:195
then
a)the total people is 195, so

b) the total bill was $1713,so
total childrend +total adults=173
but,
total adults cost= rate*number of adults
total children cost= rate*number of childe
replacing

Step 2
solve the equations,

a) isolate the x value from equation 81) and replace in eqaution (2)

replace in equation (2)

therefore, the number of adults is 51
b) now, replace the y value into equation (1) to find x

so, the number of children is 144
I hope this helps you