i'll make brainliestwhat is the solution for the system of equations? use the substitution method to solve.2x+y=20−5 y=−6x+12 enter your answer in the boxes.

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

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees

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) = .