Over the course of a year, a tractor-trailer commutes 160,000 miles across America. a. Assuming a trucker changes his tires every 40,000 miles, and that he starts with a brand new set of tires, how many sets of tires will he use in a year?

b. If the trucker changes the oil every 10,000 miles, and he starts the year with a fresh oil change, how many times will he change the oil in a year?

a. 4 sets of tires in a year.

b. 17 times a year.

Step-by-step explanation:

a. I just divided 160,000 by 40,000 to get 4 sets a year.

b. I divided 160,000 by 10,000 and then added 1 to get 17 times a year. I added one because the problem said that the trucker changes the oil in the beginning of the year.

arrange the equations with like terms in columns.

analyze the coefficients of x or y.

add the equations and solve for the remaining variable.

substitute the value into either equation and solve.

check the solution.

step-by-step explanation: