9x = -36 i wasn't given instructions for this question and i got all the other ones right but im having issues with this one for some reason.

any answers will be greatly appreciated.

What is the area of triangle abc if a = 8, b = 11, and c = 15?

Eileen purchased 3.4 pounds of apples at the total cost of $19.72. if she purchases 6.2 pounds of apples at this store, how much would it cost?

Antonia and carla have an equivalant percentage of green marbles in their bags of marbles. antonia has 4 green marbles and 16 total matbles. if carla has 10 green marbles , how many total marbles does carla have