What is an equation of the line, in point-slope form, that passes through the given point and has the given slope? point: (7,3) slope: 4/7 a) y-3=4/7(x-7) b) y-7=4/7(x-3) c) y-3=4/7(x+7) d) y-3=4/7(x-7)

Sam opened a money-market account that pays 3% simple interest. he started the account with $7,000 and made no further deposits. when he closed the account, he had earned $420 in interest. how long did he keep his account open?