If (a – b) is 9 more than (c + d) and (a + b) is 3 less than (c – d), then (a – c) is:  Choose the most appropriate option:	A) 6	B) 2	C) 3	D) 4	E) 5

Rationale: ( a – b ) – ( c + d ) = 9 and ( c – d ) – ( a + b ) = 3 = > ( a – c ) – ( b + d ) = 9 and ( c – a ) – ( b + d ) = 3 = > ( b + d ) = ( a – c ) – 9 and ( b + d ) = ( c – a ) – 3 = > ( a – c ) – 9 = ( c – a ) – 3 = > 2 ( a – c ) = 6 = > ( a – c ) = 3 answer : c
Answer: C