Answer:
15 and 3
Step-by-step explanation:
Create system of equations:
[tex]a=5b[/tex]
[tex]a+b=18[/tex]
Substitute:
[tex]5b+b=18[/tex]
[tex]6b=18[/tex]
[tex]b=3[/tex]
Substitute:
[tex]a=5(3)[/tex]
[tex]a=15[/tex]
Therefore, the two numbers are 15 and 3