Please help me out here

Which of these is and example of a literal equation? a) 6+30=6^2 b)3x-4y c)12=9+3x d)ax-by=k

Kendra had twice as much money as kareem. kendra later spent $8 and kareem earned $6. by then, the two had the same amount of money. how much money did each have originally?

Apatient is to be given 35 milligrams of demerol every 4 hours. you have demerol 50 milligrams/milliliter in stock. how many milliliters should be given per dose?