Helppppp PLZZZZZZZZZZZZZZZZZZZZZZ i need help

Answer/Step-by-step explanation:
A) The temperature in Chicago could be -10*F because -10 is to the right of -13 on the number line.
Higher Temperatures -->
o----------->I
I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I
-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10
[tex]\sf\:Q.\:Show \: that \: there \: is \: no \: positive\:integer[/tex]
[tex]\sf\:n \: for \: which \:\sqrt{n - 1} \: + \:\sqrt{n + 1}\:is[/tex]
[tex]\sf\: rational.[/tex]