On test day, a teacher sharpens 19 pencils to lend out to his students. If n represents the number of pencils that the teacher lends out, which expression represents the number of pencils he has left?On test day, a teacher sharpens 19 pencils to lend out to his students. If n represents the number of pencils that the teacher lends out, which expression represents the number of pencils he has left?On test day, a teacher sharpens 19 pencils to lend out to his students. If n represents the number of pencils that the teacher lends out, which expression represents the number of pencils he has left?On test day, a teacher sharpens 19 pencils to lend out to his students. If n represents the number of pencils that the teacher lends out, which expression represents the number of pencils he has left?