Find the percent. explain your method 30%of 50

Me i’m stuck on all these questions besides the two bottom ones

Robert has 78 tomato lants and 56 cucumber plants .he wants to plant them in rows that only have one type of plant in each row with the same number of plants in each row. how many plants should he put in each row and how many rows of each type of plant will he need

If a and b are real numbers, then |a-b| is always, sometimes or never equal to |b-a| ?