Solve : (a) `3n+7=25` (b) `2p-1=23`

Explanation

`(a)` We go stepwise to separate the variable n on the `LHS` of the equation. The `LHS` is
`3n + 7`. We shall first subtract `7` from it so that we get `3n`. From this, in the next step
we shall divide by `3` to get n. Remember we must do the same operation on both
sides of the equation. Therefore, subtracting `7` from both sides,

`3n + 7 – 7 = 25 – 7`
`3n = 18`
Now divide both sides by `3`,
`(3n)/7= 18/3`
`n=6`
`(b)` What should we do here? First we shall add `1` to both the sides:

`2p – 1 + 1 = 23 + 1`
`2p = 24`
Now divide both sides by `2`, we get `(2p)/2=24/2`
`p=12`