1)
10/(3√(х+2)= 10/(3√(-2/9+2)=10/(3√(-2+18)/9)=10/(3√(16/9))=10/3*16/9=10/4=2,5
2)
√6(√216-√150)=√1296-√900=36-30=6
4)
7х²-х-6=0
х₁=1+√(1+168) = 1+13 = 1
14 14
х₂=1-√(1+168) = 1-13 = -12/14=-6/7
14 14
4)
(2(х-у)/у)*3у/(х-у)(х+у)-6/(х+у)=6/(х+у)-6/(х+у)=0