Let's use the variables x, y and z to represent each of the three numbers.
If the sum of the three numbers is equal to 80, we have our first equation:
[tex]x+y+z=80[/tex]The first number is 8 more than the second, so:
[tex]x=y+8[/tex]The third number is 2 times the second, so:
[tex]z=2y[/tex]Using these values of z and x in the first equation, let's solve it for y:
[tex]\begin{gathered} (y+8)+y+(2y)=80 \\ 4y+8=80 \\ 4y=72 \\ y=18 \end{gathered}[/tex]Now, calculating x and z, we have:
[tex]\begin{gathered} x=18+8=26 \\ z=2\cdot18=36 \end{gathered}[/tex]Therefore the first number is 26, the second number is 18 and the third number is 36.
