Answer:
A
Step-by-step explanation:
you move the a^1 to the left which becomes a^n-a^1. then you move (n-1) to the left as well which becomes a^n-a^1/n-1=d. you switch the places and tada, the answer.
Answer:
The correct option is A) [tex]d=\frac{a_n-a_1}{n-1}[/tex]
Step-by-step explanation:
Consider the provide equation.
[tex]a_n=a_1+d(n-1)[/tex]
We need to solve the equation for d.
Subtract [tex]a_1[/tex] from both sides
[tex]a_n-a_1=a_1-a_1+d(n-1)[/tex]
[tex]a_n-a_1=d(n-1)[/tex]
Divide both sides by n-1.
[tex]\frac{a_n-a_1}{n-1}=\frac{d(n-1)}{n-1}[/tex]
[tex]d=\frac{a_n-a_1}{n-1}[/tex]
Hence, the correct option is A) [tex]d=\frac{a_n-a_1}{n-1}[/tex]