Solve the following equations
(a) 2(x + 4) = 12
(b) 3(n – 5) = 21
(c) 3(n – 5) = – 21
(d) – 4(2 + x) = 8
(e) 4(2 – x) = 8

Explanation

To solve these equations,
transpose the variables on one side and constants on
the other side, and simplify them and get the
value of a variable.

`(a) 2(x + 4) = 12`

`2x + 8 = 12`
`2x = 12 - 8`
`2x = 4`
`x = 4/2`
`x = 2`
`(b) 3(n - 5) = 21`
`3n - 15 = 21`
`3n = 21 + 15`

`3n = 36`
`n = 36/3 or n = 12`
`(c) 3(n -5) = - 21`
`3n - 15 = - 21`

`3n = - 21 + 15`

`3n = - 6`
`n = - 6/3 or n = - 2`
`(d) - 4(2 + x) = 8`
`- 8 - 4x = 8`
`- 4x = 8 + 8`
`- 4x = 16`
`x = - 16/4 = - 4`
`(e) 4(2 - x) = 8`
`8 - 4x = 8`
`-4x = 8 - 8 = 0`

or, x = 0