Answer:
[tex]n = \frac{l-a}{d}+1[/tex]
Step-by-step explanation:
[tex]l= a+(n-1)d\\[/tex]
[tex]l -a =(n+1)d[/tex]
Divide both sides of the equation by d
[tex]\frac{l-a}{d} = \frac{(n-1)}{d}\\ \\\frac{l-a}{d} = n-1\\\\\frac{l-a}{d}+1 = n[/tex]
