Question

One positive number is 8 times another number. Their difference is 70. Which of the following equations could be used to find the numbers? x - 8x = 70 8x - x = 70 x - 8 = 70

Answer 1

a = first number (larger number)
b = second number (smaller number)

a = 8b
a - b = 70  *

* since a is the larger number and their difference is positive, we want a-b.

plug the first equation into the second to get : 

a - b = 70
(8b) - b = 70
8b - b = 70

Your correct answer would be choice #2.

Answer 2

the right answer is number 2.