[tex] \sqrt{32} [/tex] = 4[tex] \sqrt{2} [/tex]
[tex] \sqrt{18} [/tex] = 3[tex] \sqrt{2} [/tex]
[tex] \sqrt{8} = 2 \sqrt{2} [/tex]
=> (5*[tex]4 \sqrt{2} [/tex]-4*3[tex] \sqrt{2} [/tex]):(-2*2[tex] \sqrt{2} [/tex] =
= [tex](20 \sqrt{2} - 12 \sqrt{2} ):(-4 \sqrt{2} ) =
8 \sqrt{2} :(-4 \sqrt{2} )
= -2[/tex]