Let the unknown be "x".
3 times a number plus 5 IS 23.
3 times a number will be "3x"
plus 5 is 23 means we will add 5 to it and equate to 23.
So, final equation:
[tex]3x+5=23[/tex]We can now solve for x using algebra. Shown below:
[tex]\begin{gathered} 3x+5=23 \\ 3x=23-5 \\ 3x=18 \\ x=\frac{18}{3} \\ x=6 \end{gathered}[/tex]The number is 6