Sequence 3

Write the first 6 members of an arithmetic sequence: a5=15, a11=39.

Final Answer:

a1 =  -1
a2 =  3
a3 =  7
a4 =  11
a5 =  15
a6 =  19

Step-by-step explanation:

a5​=15 a11​=39  a5​= a1​ + (5−1)d a11​= a1​ + (11−1)d  d=5−11a5​−a11​​=5−1115−39​=4  a1​=a5​+(1−5)⋅ d=15+(1−5)⋅ 4=−1
a2​=a5​+(2−5)⋅ d=15+(2−5)⋅ 4=3
a3​=a5​+(3−5)⋅ d=15+(3−5)⋅ 4=7
a4​=a5​+(4−5)⋅ d=15+(4−5)⋅ 4=11
a5​=a5​+(5−5)⋅ d=15+(5−5)⋅ 4=15
a6​=a5​+(6−5)⋅ d=15+(6−5)⋅ 4=19

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