What is the equation for a quadratic function

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?

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?

Aline passes through 3,7 and 6,9 what equation represents the line