Is this equation linear or not? y = 2x²

When can u say there is no solution for a system of linear inequalities? explain your answer and show with a system and graph

I've never been good at math he told he loves but he keeps cheating on me, so it ain't adding up sis

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