Koft operation

Koft operation is a. In this operation, we use two numbers separated by a vertical score, multiplying these two numbers twice, each one adding square of the both numbers given at a time. Then we subtracting the two resulting numbers to reveal the answer.

For example, lets solve for 12|16. The first operation we write is (12×16)+12²=192+144=336. The second operation is (12×16)+16²=192+256=448. Then we subtract, 448−336=112. So the value of 12|16 is 112.

There is a faster, simpler way to solve it, by simply multiplying the sum and difference of these two numbers. For 12|16, the sum is 28 (since 12+16) and the difference is 4 (since 16−12). So we multiply 28×4=112. So 112 is the same answer as the more complex operation above.

The more complex operation is called the "time square operation", while the simpler operation is called the "hanging operation".

Explanation
The first operation, performed on $$a|b$$, is $$ab + {a}^{2}$$. The second operation is $$ab + {b}^{2}$$. The difference of these two is $$ab + {a}^{2} - ab - {b}^{2} \times -1$$, which is simply $$-(a+b)(a-b)$$ by the difference of two squares.