Question

The Business Club's thrice yearly car wash serviced 398 cars this year. A total of 84 more cars participated in May than in November. A total of 43 fewer cars were washed in July than in November. How many cars were washed during each month?

Answer 1

Let x be the number of cars participated in November. Then (x+84) is the number of cars participated in May, (x-43) is the number of cars participated in July.If 398 cars were serviced during three months, then equation x+(x+84)+(x-43)=398 holds true.
Open brackets x+x+84+x-43=398 and collect similar terms 3x+41=398, subtracting 41 from both sides gives 3x=357, divide by 3 and finally obtain x=119. Thus, x=119 is the number of cars participated in November, x+84=119+84=203 is the number of cars participated in May,
x-43=119-43=76 is the number of cars participated in July.