one number is 6 more than another. If the sum of the smaller number and 3 times the larger number is 34, find the two numbers?

Let y be the larger number and x the smaller one.

x + 6 = y
Rewrite as
-x + y = 6
x + 3y = 34
Add the last two equations:
4y = 28
Divide both sides by 4 to solve for y. Then x will be easy.