$\"\"$

The equation is $\"2$ .

$\"2$ (Apply distributive property: a (b + c) = ab + ac)

$\"2$ (Multipy: $\"2$ ) $\"\"$

$\"2$ (Subtract $\"2$ from each side)

$\"12$ (Simplify)

$\"12$ (Add 1 to each side)

$\"d$ (simplify) $\"\"$

Check:

To check the solution , substitute $\"d$ in the original equation.

$\"2$ (Substitute $\"d$ )

$\"2$ (Add: 13 + 6 = 19)

$\"38$ (Multipy $\"2$ )

$\"38$ (Subtract: $\"39$ ) \ \ $\"\"$

The solution is $\"d$ . \ \