can someone please help me with this i have no clue how to do this and i don’t know where to plot the points of the function! this is my last resort, i really need some help:(

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

What is the value of x in the diagram below?

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)