b/a−b+c+2a+c/b−a−c-b−cb−a−c
问题描述:
+b a−b+c
-2a+c b−a−c
b−c b−a−c
答
+b a−b+c
−2a+c b−a−c
b−c b−a−c
=
+b a−b+c
=2a+c−b+c b−a−c
+−b b−a−c
=2a−b+2c b−a−c
=-2.2a−2b+2c b−a−c