网址:http://m.1010jiajiao.com/timu_id_762212[举报]
下列各式中,运算正确的是( )
A.3a-4a+a=0 B.x3 +x3 =2x6 C.5x2 -2xy2 =3xy D.5m-m=4
A.6m-5m=1 A n2+n2=n4 C.3a2+2a3=5a5 D.3x2y-4yx2 =-x2y
A. B.
C. D.