The half-life of sodium-22 is 2.6 years. a sample contains 800 mg of this isotope.

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

How do you solve a question like this?

Diane’s bank is offering 5% interest, compounded monthly. if diane invests $10,500 and wants $20,000 when she withdrawals, how long should she keep her money in for? round to the nearest tenth of a year.