Answer :

To solve the equation [tex]\( 6(d + 1) - 2d = 54 \)[/tex], follow these steps:

1. Distribute the 6 on the left side of the equation:
[tex]\[ 6(d + 1) - 2d = 54 \][/tex]
becomes
[tex]\[ 6d + 6 - 2d = 54 \][/tex]

2. Combine like terms:
[tex]\[ 6d - 2d + 6 = 54 \][/tex]
simplifies to
[tex]\[ 4d + 6 = 54 \][/tex]

3. Isolate the term with [tex]\( d \)[/tex] by subtracting 6 from both sides:
[tex]\[ 4d + 6 - 6 = 54 - 6 \][/tex]
simplifies to
[tex]\[ 4d = 48 \][/tex]

4. Solve for [tex]\( d \)[/tex] by dividing both sides by 4:
[tex]\[ d = \frac{48}{4} \][/tex]
which simplifies to
[tex]\[ d = 12 \][/tex]

So, the solution is:
[tex]\[ \boxed{12} \][/tex]