Help please- it’s for an assessment :/

Answer soon(fast) 15 pts-brainliest? for right answer with small explination a restaurant catered a party for 40 people. a child’s dinner (c) cost $11 and an adult’s dinner (a) cost $20. the total cost of the dinner was $728. how many children and adults were at the party? use the table to guess and check.(i couldn't get the graph onto the question)                                8 children and 32 adults9 children and 31 adults10 children and 30 adults12 children and 28 adults

Plzzz i beg u so much asaaaap ! what is the slope of this line? enter your answer in the box.

What is the solution to the system of equation graphed belowa.(0,-4)b.(2,5),1),-3)