Hannah had $58 to spend on gifts. She purchased some key chains that cost $3 each. After shopping, Hannah had $16 left.
Which equation could be used to find the total number of key chains, n, that
Hannah purchased?
It’s a part a question

Apatient is given 50 mg dose of medicine the medicines effectiveness decreases every hour at a constant rate of 40% what is the exponential decay function that models this scenario how much medicine will be left in the patients system after 2 hours

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

Abouncy ball is released from a certain height. on the first bounce, it travels 32cm. with each subsequent bounce, it travels 9/10 the distance of the previous bounce. what is the total distance that the ball has traveled when it completes its 25th bounce?