4.
[tex]\sqrt{64}=8\\\\8\dfrac17=8.14285714...\\\\8.\overline{14}=8.14141414...\\\\ \dfrac{15}2=7,5\\\\\\ \boxed{\ \dfrac{15}2\ \ \textless \ \ \sqrt{64}\ \ \textless \ \ 8.\overline{14}\ \ \textless \ \ 8\dfrac17\ }[/tex]
5.
[tex] \sqrt{18} [/tex] doesn't belong with the other three because it is irrational number
The other three can be expressed as a ratio between two integers.
[tex]-\dfrac{10}2=\dfrac{-10\ }2\\\\-13.4=-13\frac4{10}=\frac{-134}{\ 10}\\\\ 22.\overline7=22\frac79=\frac{205}9\\\\\\ \sqrt{18}=\sqrt{9\cdot2}=\sqrt9\cdot\sqrt2=3\sqrt2[/tex]
