Question

Please tell the formula and answer for the photo given above​

Answer 1

Answer:

11.................

Step-by-step explanation:

$ab + a {}^{2} - ab + b {}^{2} + c {}^{2} - ac$

$a {}^{2} + b {}^{2} + c {}^{2} - ac$

$1 {}^{2} + 2 {}^{2} + ( - 2) {}^{2} - 1 \times ( - 2)$

$1 + 4 + 4 - ( - 2)$

$1 + 4 + 4 + 2$

$11$