Hey there!
To start, first let the variable, x, represent your first unknown number. Now, because the second number is 5 times the first, this will be represented as 5x (you simply multiply 5 to your variable of the first number, x).
Now, since the sum of the two numbers are 42, you can represent this by setting up this equation:
5x+x=42
Combine your like terms (terms of the same variable and are raised to the same power):
5x+x=42
6x=42
Divide both sides by 6 to solve for x:
6x/6=42/6
x=7
Because x represents the first number, your first number would be 7.
Now, since the second number is 5 times the first, you can find the second number by multiplying x by 5:
x=7
7*5=35
Your second number is 35.
To check if both numbers are correct, you can add your first number, 7 to your second number, 35, to see if you get 42 since you know their sum must be 42:
7+35=42
Therefore, your final answer would be that the first number is 7, and the second number is 35.
Hope this helps, and have a marvelous day! :)