Is there no solution, one solution or many solutions for 21+2.5w=6+5.7w-3.2w+15?

X+ y = 5 ; x - y =3 solve using linear combination

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) = .

During each minute of a comedy show, carlin laughs 55 times. carlin watches 33 comedy shows every day, and each show is 40 minutes long. how many times does carlin laugh every day due to the comedy shows?