Question 924988
Let L = the larger number and
Let s = the smaller number
From the problem statement we have
(1) s + L = 103 and
(2) L - 4*s = 8
You need, and have, two equations to solve for two unknowns (the two numbers).
You can use any of the techniques you learned to solve simultaneous equations. Let's use substitution. Solve (2) for L and get
(3) L = 8 + 4*s 
Now put L of (3) into (1) and get
(4) s + 8 + 4*s = 103 or
(5) 5*s = 103 - 8 or
(6) 5*s = 95 or
(7) s = 95/5 or
(8) s = 19
Now put s of (8) into (2) to get
(9) L - 4*19 = 8 or
(10) L = 8 + 4*19 or
(11) L = 8 + 76 or
(12) L = 84
Now use (2) to check your answer.
Is (L - 4*S = 8)?
Is (84 - 4*19 = 8)?
Is (84 -76 = 8)?
Is (8 = 8)? Yes
Answer: The smaller number is 19 and the larger number is 84.
REM: you need to write two independent equations to solve for two unknowns. If you have three unknowns, like in many coin problems, you need three independent equations, etc. etc.