The walker family and the goodman family ate going to the cinema. the walkers pay £22 for 2 adults tickets and 1 child ticket. the goodmans pay £26 for 1 adult and 3 child tickets.
how much does a child ticket cost?

The walkers pay 22 for 2 adult tickets and one child ticket so we can say:

2a+c=22, The question wants to find the cost of a child ticket so solve this for a...

2a=22-c

a=(22-c)/2

Now we are told that the Goodmans by 26 for one adult and three childrens tickets so:

a+3c=26, now use (22-c)/2 in this equation for a and you get:

(22-c)/2+3c=26

(22-c+6c)/2=26

22+5c=52

5c=30

c=6

So a child's ticket costs £6.00  

In all honesty, there really is no “work” per say to show. mainly it’s just using the process of elimination. the question is asking which domain(s) would be the most appropriate for the function c(n). n is the number of observed vehicles so right away, 1, 2, and 3 can be eliminated.why? 1, 2 start in the negatives and therefore it is impossible to observe negative cars. so, #4 would be the best answer to the given problem.

A. -10 is the value of x