去括号,并合并同类项::(1)2n-(2-n)+(6n-2) (2)a+3(5a-2b)-2(3a-b)
问题描述:
去括号,并合并同类项::(1)2n-(2-n)+(6n-2) (2)a+3(5a-2b)-2(3a-b)
答
2n-(2-n)+(6n-2)
=2n-2+n+6n-2
=9n-4
(2)a+3(5a-2b)-2(3a-b)
=a+15a-6b-6a+2b
= 10a-4b