algebra
posted by victor .
the larger of two numbers is 1 more than twice the smaller.the sum of the numbers is 20 less than three times the larger.find the numbers

Look at my answer to Ulises a few lines down for hint.

i know i just need help setting the equation

Ok, call big one b
call small one s
b = 1 + 2 s
b + s = 3 b  20 
can u help me work it out please

from the first equation you know that you can use the quantity (1 + 2 s) for b
so do that
1 + 2 s + s = 3 (1 + 2 s)  20
or
1 + 3 s = 3 + 6 s  20
solve that for s, then go back and find b 
b=13,s=6