The sum of 15 and the product of 5 and v

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line

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?

Can someone me with this problem . show your work .