define the 3 numbers
smallest number = x
middle number = x + 2
largest number = x + 4
write the equation
sum of the smallest number and twice the middle number
[tex]\begin{gathered} x+2(x+2) \\ x+2x+4 \\ 3x+4 \end{gathered}[/tex]20 more than the largest number
[tex]\begin{gathered} x+4+20 \\ x+24 \end{gathered}[/tex]equal the expressions
[tex]\begin{gathered} 3x+4=x+24 \\ 3x-x=24-4 \\ 2x=20 \\ x=\frac{20}{2} \\ x=10 \end{gathered}[/tex]the numbers should be 10, 12 and 14
[tex]\begin{gathered} 10+2\cdot(12)=14+20 \\ 10+24=34 \\ 34=34 \end{gathered}[/tex]