The second term of an arithmetic sequence is 7. the sum of the first 4 terms of the arithmetic sequence is 12. find the first term, and the common difference, d, of the sequence.

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A) if $50000 is invested in a bank account that pays 9.3% of interest compounded on a six-monthly basis, how much money will be in the account after 3 and 12 years? b) if matusalen's father had put $2.0 in the bank when he was born and there, how long would matusalen have had to his death (969 years later) if the interest was 7% per year composed each month and weekly?