f.1 maths (用方程解答）

1)peter read 5 pages less than 2/3 of a novel on the first day. He read 2 pages than
3/5 of the remainder on the second day. 18 pages are still not read.find the total number of pages of this novel.
2)if the values of the algebraic expressions 1/2x-5 and x+1 are reversing numbers(i.e. the magnitudes of two numbers are equal ,but their signs are different),
(a)write an equation to represent the information.
(b)find the value of x.