Which of the following equations should be used to solve the following problem: cos x = 5/18 a: x=cos^-1 8/15
b: x=8/cos15
c: x=15cos8
d: 18cosx=5

PLEASE HELP!! WILL AWARD BRAINLIEST

Suppose you are an avid reader and are looking to save money on the cost of books instead of paying about $20 for each book, you decide to look into purchasing a kindle for $120 you can purchase e-books for about $5 each 1. find the slope-intercept equation for the cost of the hard copy of books using x to represent the number of books 2. find the slope-intercept equation for the cost of the kindle with cost of e-books using x to represent the number of books

Solve each quadratic equation by factoring and using the zero product property. 14x - 49 = x^2

The price of a visit to the dentist is calculated according to the formula 50+100n50+100n where nn is the number of cavities the dentist finds. on your last visit to the dentist, 22 cavities were found. what was the cost of your visit?