Answer:
 1) The system of equations is  and
 and 
 2) The first number is  and the second number is
 and the second number is 
Step-by-step explanation:
 1) Let be "x" the first number and "y" the second number.
 Remember that:
 a- The word "times" indicates multiplication.
 b- A sum is the result of an addition.
 c- "Is" indicates this sign:  
 Then, the sum of 5 times "x" and 4 times "y" is 75, can written as:
 
 And "The sum of the two numbers is 18" can written as:
 
 Therefore, the System of equations is:
 
 
 2) You can use the Elimination Method to solve it:
 - Multiply the second equation by -5, add the equations and then solve for "y":
 
 - Substitute the value of "y" into any original equation and solve for "x":
 