Nels needs 15 gallons of lemonade for a company picnic. if he buys the lemonade in quart bottles, how many bottles does nels need to buy?

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .