If a/b=c/d then prove that a+b/c-d=c+d/c-d​

1. which of the following is a search engine? a) mozilla firefox b)internet explorer c)google d)safari 2. which of the following statements is true? a) all search engines will provide the same results when you enter the same query. b) all search engines use the same amount of advertisements. c) some search engines are also browsers. d) search engines often provide different results, even when you enter the same query.