One number is 6 times a first number. a third is 100 more than the first number. if the sum of the three numbers is 708, find the numbers

Say the first number is x, you would then have x and 6x and then x + 100. If you add all these together you get 8x + 100 = 708. You then subtract both sides by 100 and get 8x = 608. Divide both sides by 8 and you get 608/8 which = 76.