To factorize an expression, we just remove the common factor and multiply by the remaining terms.
[tex]ab+ac=a(b+c)[/tex]
To find the common factor, we just need to look for an equal factor in all terms of the expression. On our problem we have two terms, and both of them are multiplied by (2c + 13), therefore, the factorized version of our expression is
[tex]\begin{gathered} 5c(2c+13)-(2c+13)=5c\cdot(2c+13)-1\cdot(2c+13) \\ =(5c-1)(2c+13) \end{gathered}[/tex]
