A class of 340 students went on a field trip. They took 8 vehicles, some cars, and some buses. Find the number of cars and the number of buses they took if each car holds 5 students and each bus-hold 55 students.

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

2nd one in the first row is correct

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.