999乘111加3333乘667 和 1001乘1001减1001 这两个用简便算····很急啊······

999X111+333X667
= 333X3X111+333X667
= 333X333+333X667
=333X(333+667)
=333X1000
=333000
1001X1001-1001
=1001X(1001-1)
=1001X1000
=1001000

数学 999乘111加3333乘667 这题有没有错啊？
1001×1001-1001
=1001×（1000+1）-1001
=1001×1000+1001×1-1001
=1001000

999乘111加333乘667
= 333乘3乘111加333乘667= 333乘333加333乘667
=333乘（333+667）=333乘1000=333000
1001乘1001减1001 =1001*1001-1*1001
=(1001-1)*1001=1001000

999乘111加333乘667 =3*333*111+3*111*667
=(333+667)*3*111=333000
1001乘1001减1001 =1001*1001-1*1001
=(1001-1)*1001=1001000

999乘111加333乘667
= 333乘3乘111加333乘667
= 333乘333加333乘667
=333乘（333+667）
=333乘1000
=333000
1001乘1001减1001
=1001乘（1001-1）
=1001乘1000
=1001000