Find the indicated terms.
-If the third and fourth terms of an arithmetic sequence are -7 and -10, what are the first and second terms?
A) $a _ { 1 } = 10 , a _ { 2 } = 7$
B) $a _ { 1 } = - 1 , a _ { 2 } = - 4$
C) $a _ { 1 } = - 4 , a _ { 2 } = - 1$
D) $a _ { 1 } = 7 , a _ { 2 } = 10$

Question

Find the indicated terms.
-If the third and fourth terms of an arithmetic sequence are -7 and -10, what are the first and second terms? 
A) $a _ { 1 } = 10 , a _ { 2 } = 7$
B) $a _ { 1 } = - 1 , a _ { 2 } = - 4$
C) $a _ { 1 } = - 4 , a _ { 2 } = - 1$
D) $a _ { 1 } = 7 , a _ { 2 } = 10$

Quizplus · Accepted Answer

In an arithmetic sequence, the difference between consecutive terms is constant. The difference between the third and fourth terms is -10 - (-7) = -3. Therefore, to find the first and second terms, we add the common difference of -3 to the third term twice for the first term and once for the second term: $a_1 = -7 + (-3) + (-3) = -13$, $a_2 = -7 + (-3) = -10$. However, there seems to be a mistake in my explanation regarding the calculation of the first and second terms based on the provided options. Correctly, to find the first and second terms, we subtract the common difference of -3 from the third term: $a_2 = -7 - (-3) = -4$, $a_1 = -4 - (-3) = -1$, which matches option B.

Find the Indicated Terms a1=10,a2=7a _ { 1 } = 10 , a _ { 2 } = 7a1​=10,a2​=7

Find the Indicated Terms $a _ { 1 } = 10 , a _ { 2 } = 7$