2.8-5 and 4 / 9 + 7.2-3 and 5 / 9 off formula calculation

2.8-5 and 4 / 9 + 7.2-3 and 5 / 9 off formula calculation

Mm-hmm

9.5-8.9 + 11.5-6.1 =? Simple calculation

9.5-8.9+11.5-6.1=(9.5+11.5)-(8.9+6.1)=21-15=6

Simplification √ 8 - √ 2 (√ 2 + 2)
It's the second radical. It's strange that I've calculated several times, and the result is 2 + 2 √ 2, but there's no choice in the answer
√8-√2（√2+2）
=2√2-√2（√2+2）
=√2（√2+2）
=√2*√2 + 2√2
=2+2√2
Please tell me what's wrong,

√8-√2（√2+2）
=2√2-√2（√2+2）
=√2（√2+2）……………… Here it should be √ 2 (2 - √ 2-2) to extract the common factor
=√2*√2 + 2√2
=2+2√2
The final result is √ 2 (2 - √ 2-2) = √ 2 (- √ 2) = - 2