Given the simultaneous equations : 2^x=3^y, x+y= 1, find x

Rachel reads 1/5 of the pages of a book plus 12 pages on the first day. on the second day, she reads 1/4 of the remaining pages plus 15 pages. on the third day, she reads 1/3 of the remaining pages plus 18 pages. on the fourth day, she reads the remaining 70 pages. how many total pages are in the book?

For f(x) = 3x+1 and g(x) = x2 - 6, find (g/f)(x)

If the value of cos330°is√3/2 then find cos 165°.