A length is measured as 21 cm correct to 2 significant figures. What is the lower bound for the length?

Abouncy ball is dropped such that the height of its first bounce is 5.5 feet and each successive bounce is 64% of the previous bounce's height. what would be the height of the 7th bounce of the ball? round to the nearest tenth (if necessary).

How do i work this problem out using the equation a=pe^rt

The system of equations graphed below has how many solutions?