Answer: 24
Step-by-step explanation:
x = smaller number
8x = larger number, since it's 8 times larger than the smaller
8x-x = 7x = difference of the numbers
That difference is 21, so we can say 7x = 21 which solves to x = 3
The smaller number is 3 and the larger is 8x = 8*3 = 24
As a check: 24-3 = 21, which confirms the answer.