these are the steps to solve this question. and I used Substitution to explain it.
1. Identify what you need.
2. Write out your two different equations.
30e + 115h = 1457 and e + h = 18
3. Identify witch way you would proceed. Substitution or Elimination.
4. Solve using you prefers way. for me I will use substitution. find either e first or h. this doesn't matter witch you start with.
5. Take one of the equations and get a variable alone. TIP: use the one share that variable stands alone.
6. When variable is alone. put what ever it equals on the other equation and solve. Do this once.
7. When solved take that answer and plug it into its desined spot and solve to find the other answer.
8. Alone both solutions from the answer to what e and h are.