`a)997xx4+997xx6=997xx(4+6)=997xx10=9970`
`b)458xx19+458xx27=458xx(19+27)=458xx46=21068`
`c)1863xx85-55xx1863=1863xx(85-55)=1863xx30=55890`
`d)618xx134+618xx256=618xx(134+256)=618xx390=241020`
`997 xx 4 + 997 xx6`
` = 997 xx ( 4 + 6)`
` = 997 xx 10`
` = 9970`
________________________
` 458 xx19 + 458 xx 27`
` = 458 xx ( 19 + 27)`
` = 458 xx 46`
` = 21068`
________________________
` 1863 xx 85 - 55 xx 1863`
` = 1863 xx (85 - 55)`
` =1863 xx 30`
` = 55890`
________________________
`618 xx 134 + 618 xx 256`
` = 618 xx ( 134 + 256)`
` = 618 xx 390`
` = 241020`
`997xx4+997xx6`
`=997xx(6+4)`
`=997xx10`
`=9970`
`458xx19+458xx27`
`=458xx(19+27)`
`=458xx46`
`=2748`
`1863xx85-55xx1863`
`=1863xx(85-55)`
`=1863xx20`
`=37260`
`618xx134+618xx256`
`=618xx(134+256)`
`=618xx390`
`=241020`