`@``text{Bơ}`

`a) 7 + x = 312`

`x = 312 - 7`

`x = 305`

Vậy `x = 305`

`b) 25 - x = 14`

`x = 25 - 14`

`x = 11`

Vậy `x = 11`

`c) 451 + (x - 218) = 876`

`x - 218 = 876 - 451`

`x - 218 = 425`

`x = 425 + 218`

`x = 643`

Vậy `x = 643`

`d) 735 - (457 + x) = 124`

`457 + x = 735 - 124`

`457 + x = 611`

`x = 611 - 457`

`x = 154`

Vậy `x = 154`

`e) (315 - x) + 264 = 327`

`315 - x = 327 - 264`

`315 - x = 63`

`x = 315 - 63`

`x = 252`

Vậy `x = 252`

`f) (x - 42) - 152 = 61`

`x - 42 = 61 + 152`

`x - 42 = 213`

`x = 213 + 42`

`x = 255`

Vậy `x = 255`

`g) 312 - (x + 12) = 169`

`x + 12 = 312 - 169`

`x + 12 = 143`

`x = 143 - 12`

`x = 131`

Vậy `x = 131`

`h) 412 + (x - 47) = 600`

`x - 47 = 600 - 412`

`x - 47 = 188`

`x = 188 + 47`

`x = 235`

Vậy `x = 235`