I have my problem of my own:
The sum of the bigger and the smaller number is 20. If the bigger number is 10 more than the smaller number, find the numbers.
Lets say:
x=smaller number
x+10=bigger number
Find the sum:
x+x+10=20
Add all like terms
2x+10=20
Subtract 10 to both sides.
2x=10
Divide both sides by 2
x=5
Therefore, the smaller number is 5, and the bigger number is 15. Hope this helps =)