SOLUTION: Hi everyone i hope someone can help me . im using the
{{{ Sn= (n/2) (2a +(n-1)d) }}} formula with a=first term and d= common difference
im trying to solve for a if S21=315
Algebra ->
Sequences-and-series
-> SOLUTION: Hi everyone i hope someone can help me . im using the
{{{ Sn= (n/2) (2a +(n-1)d) }}} formula with a=first term and d= common difference
im trying to solve for a if S21=315
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Question 357859: Hi everyone i hope someone can help me . im using the
formula with a=first term and d= common difference
im trying to solve for a if S21=315 and d=3 .im a little confused what to do when i get
so i need to solve for a ?? this is where i get my problem. how do i get a on its own??
Iv tried
im not sure from here?? do i just subtract 651 from both sides to find a. im not sure that answer dose not look right.?? any help would be appreciated :) Found 2 solutions by mobosecomin, mananth:Answer by mobosecomin(1) (Show Source):
You can put this solution on YOUR website! ok so i solved this myself it was just a silly order of precedence problem i was having
when i got i should have multiply everything in the brackets by 10.5
:)
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