NEED HELP ASAP

Tickets to a family concert cost $10 for adults and $3 for children. The concert
organizers collected a total of $900 from ticket sales.
Given the function 10A + 3C = 900:
A) Write an equation to represent C as a function of A. (In essence, solve the equation
for C).
B) Write an equation to represent A as a function of C. (In essence, solve the equation
for A)
**Use math type to type your answer**