Question

(3-√2)^2-(3+√2)^2-3(3-√2)(3-√2)=

Answer 1

9 - 6√2 + 2 - 9 + 6√2 + 2 - 3 ( 9 - 2 )
9 + 2 - 9 + 2 - 3 x 7
2 + 2 - 21
4 - 21
- 17

Answer 2

$(3- \sqrt{2})^{2} -(3+ \sqrt{2})^{2} -3(3- \sqrt{2})(3- \sqrt{2})= \\ \\ (9-6 \sqrt{2}+2)-(9+6 \sqrt{2} +2)-3(9-3 \sqrt{2} -3 \sqrt{2} +2)= \\ \\ -12 \sqrt{2} -3(11-6 \sqrt{2} )= \\ \\ -12 \sqrt{2} +6 \sqrt{2} -33= \\ \\= -6 \sqrt{2} -33$