Given are the first three terms of a sequence that is arithmetic. Find a1 and d.
-9, 13, 17
A) $a _ { 1 } = 9 ; d = - 12$
B) $\mathrm { a } _ { 1 } = 9 ; \mathrm { d } = 12$
C) $a _ { 1 } = 9 ; d = - 4$
D) $a _ { 1 } = 9 ; d = 4$

Question

Quizplus · Accepted Answer

The first term $a_1$ is 9, and the common difference $d$ is found by subtracting the first term from the second term: $13 - 9 = 4$.

Given Are the First Three Terms of a Sequence That a1=9;d=−12a _ { 1 } = 9 ; d = - 12a1​=9;d=−12

Given Are the First Three Terms of a Sequence That $a _ { 1 } = 9 ; d = - 12$