To solve this equation, we can use the associative property of addition, which states that the order in which we add numbers does not change the sum. In other words, (a + b) + c = a + (b + c).
Applying this property, we can rearrange the equation as follows:
(+1) + ١٢ = (6+ (...))+۱۲
(+1 + 6) + ١٢ = (... + ۱۲) + ۱۲
7 + ١٢ = (... + ۱۲) + ۱۲
Now, we can see that both sides of the equation have the same number 12 added to them. To isolate the missing number, we can subtract 12 from both sides:
7 + ١٢ - 12 = (... + ۱۲) + ۱۲ - 12
7 = ... + ۱۲
Therefore, the missing number is 0.
We used the associative property of addition to rearrange the equation and isolate the missing number.