Which of the following pair of algebraic expression will add up to give 12xy - 7?
-7xy + 12; 12xy - 2; 9xy + 8 and -2xy - 25
Adding like terms in each of the options provided, we get
-7xy + 12; 12xy - 2; 9xy + 8 and -2xy - 25
-7xy + 12xy + 9xy - 2xy + 12 - 2 + 8 - 25 = 12xy -7