Question

Va rog frumos exercitiul 2.

Answer 1

a)

$x=\frac{3\sqrt{3}*5\sqrt{5}}{8\sqrt{15}}=\frac{15\sqrt{15}}{8\sqrt{15}}=15/8$

b)

$\frac{-2\sqrt{3} }{3\sqrt{2} } =Amplificam~cu~radical~din~2=\frac{-2\sqrt{3}*\sqrt{2}  }{3\sqrt{2} *\sqrt{2} }=\frac{-2\sqrt{6} }{3*2} =\frac{-\sqrt{6} }{3}$

c)

a=(1-√2)²+(√2+1)²-2(√2-1)(√2+1)

a=1-2√2+2+2+2√2+1-2(2-1)

a=1-2√2+2+2+2√2+1-2

a=1+2+2+1-2

a=4

√a=√4=2∈N