Đáp án `+` lời giải chi tiết:

a) `{1995xx87+1000}/{89xx1995-2990}`

`={1995xx87+1000}/{1995xx(87+2)-2990}`

`={1995xx87+1000}/{1995xx87+1995xx2-2990}`

`={1995xx87+1000}/{1995xx87+3990-2990}`

`={1995xx87+1000}/{1995xx87+1000}`

`=1`

b) `175xx1274-175xx273-175`

`=175xx(1274-273-1)`

`=175xx1000`

`=175000`

c) `{1991}/{1990}xx{1992}/{1991}xx{1993}/{1992}xx{1994}/{1993}xx{995}/{997}`

`={1991xx1992xx1993xx1994xx995}/{1990xx1991xx1992xx1993xx997}`

`={1994xx995}/{1990xx997}`

`={(1990+4)xx995}/{1990xx997}`

`={1990xx995+4xx995}/{1990xx997}`

`={1990xx995+2xx1995}/{1990xx997}`

`={1990xx(995+2)}/{1990xx997}`

`={1990xx997}/{1990xx997}`

`=1`

𝕮𝖊𝖑𝖎𝖆 𝕮𝖑𝖆𝖎𝖗𝖊

 

`h ) (1995 xx 87 +1000)/(89 xx 1995 - 2990)`

`= (1995 xx 87+1000)/((87+2) xx 1995 - 2990)`

`= (1995 xx 87+ 1000)/(87xx1995 + 2 xx 1995 - 2990)`

`= (1995 xx 87 + 1000)/(87 xx 1995 + 3990 - 2990)`

`= (1995 xx 87 + 1000)/(87 xx 1995 + 1000)`

`= 1`

`n ) 175 xx 1274 - 175 xx 273 - 175`

`= 175 xx (1274 - 273 - 1)`

`= 175 xx 1000`

`= 175000`

`m ) 1991/1990 xx 1992/1991 xx 1993/1992 xx 1994/1993 xx 995/997`

`= (1991 xx 1992 xx 1993 xx 1994 xx 995)/(1990 xx 1991 xx 1992 xx 1993 xx 997)`

`= (1991 xx 1992 xx 1993 xx 997 xx 2 xx 995)/(995 xx 2 xx 1991 xx 1992 xx 1993 xx 997)`

`= 1`

`#dtkc`