Answer:
around 2.67 (decimal form)

Explanation:
12( x - 1 ) = 40 (given)
12x - 12 = 40 (distribute)
12x - 12 + 12 = 40 + 12 (add 12 both sides)
12x = 40 + 12 (cancel 12 left side)
52 (combine like terms)
12x = 52/12 (divide 12 both side)
x = 8/3 (answer)
Around 2.67 just in case questions ask for roundings...