`a) (y + 5,678) : 7 = 3,542 + 18,754`

`(y + 5,678) : 7 = 22,296`

`y + 5,678 = 22,296 xx 7`

`y + 5,678 = 156,072`

Vậy `y = 156,072`

............................................

`b) 758.293 - y = 12.547 + 325.487`

`758.293 - y = 338,034`

`y = 758.293 - 338,034`

`y = 420,259`

Vậy `y = 420,259`

Đáp án `+` Giải thích các bước giải :

`a)` `(y+5,687):7=3,542+18,754`

      `(y+5,687):7=22,296`

           `y+5,687=22,296xx7`

           `y+5,687=156,072`

                      `y=156,072-5,687`

                      `y=150,385`

`b)` `758,293-y=12,547+325,487`

       `758,293-y=338,034`

                     `y=758,293-338,034`

                     `y=420,259`