Answer:
1st = 13
2nd = 21
3rd = 36
Step-by-step explanation:
Let the first number be
f
The second of three numbers is 8 more than the first,
f + 8
third number is 3 less than 3 times the first.
3f - 3
---------------------------
the third number is 15 more than the second,
3f - 3 = (f + 8) + 15
3f - 3 = f + 23
Subtract f from both sides
2f - 3 = 23
add 3 to both sides
2f = 26
Divide both sides by 2
f = 13
f + 8 = 13 + 8 = 21
3f - 3 = 3(13) - 3 = 36
