we make a equation depending of the days
[tex]T=2000-50d[/tex]Where T is the total of pencils
In this equation we are going to subtract 50 pencils for each day from the original 2000
to know the days where are 950 pencils we replace the total by 950 and solve d
[tex]\begin{gathered} 950=2000-50d \\ 50d=2000-950 \\ 50d=1050 \\ d=\frac{1050}{50} \\ \\ d=21 \end{gathered}[/tex]the number of days is 21
