first question is marked correctly ... use the Pythagorean theorem to answer the second question.
1) For some reason the system indicates that there is more than one answer. Do you see any more answers?
2) I knew it was Pyth. Theorem so I wrote a^2+b^2 and the system counted it wrong. (Worried)
1. Since the system catches ±1%, you should write everything that in the range 7.29109 ± 1% = 7.29109 ± 0.0729109 = [7.21818 , 7.364].
You should thus add the third and last choice.
2. Maybe it is a "vector space" and the system wants to hear a+b and not the magnitude a^2+b^2. However, the way it is asked I agree your answer is right.
THAT helped out a whole whole lot.