Answer:
a + b = 50 (Two numbers total 50)
b = a - 6 (one number is 6 less than the other)
Since we have a value, we can use the substitution metod:
a + a - 6 = 50
Simplify:
2a - 6 = 50
From here, you should know how to isolate a variable--add 6 then divide by 2 in this case. That'll give you a, and you'll be able to use that to solve for b.