"Fifteen is thirteen less than twice a number."
We can put the numbers in the sentence before translating it to an algebraic expression in order to be easier to do it:
• 15 is 13 less than 2 a number."
Now, we are left with words, which we can also translate:
• "less than" is -
,• "is" is =
,• "number" is ,x ,as we do not know the value.
Finally, joining all the translations in an algebraic expression:
[tex]15=13-2x[/tex]