[tex]Distributive\ property:\\\\a\times(b+c)=a\times b+a\times c\\\\(b+c)\times a=b\times a+c\times a\\=====================[/tex]
[tex]5\times28=5\times(20+8)=5\times20+5\times8=100+40=140\\\\104\times8=(100+4)\times8=100\times8+4\times8=800+32=832\\\\129\times6=(130-1)\times6=(100+30-1)\times6\\=100\times6+30\times6-1\times6=600+180-6=780-6=774[/tex]