Question

cine ma poate ajuta dau coroana

Answer 1

a).

$(\sqrt3+2)^2+4(5-\sqrt3)-(\sqrt7-3)(\sqrt7+3)=\\\\3+4\sqrt3+4+20-{4\sqrt3}-(7+3\sqrt7-3\sqrt7-9)=27+2=29$

b).

$x(x+4)-(x+2)^2=x^2-4x-x^2-4x-4=-8x-4$

c).

$(2x-1)^2-(x+1)^2=4x^2-4x-1-x^2-2x-1=3x^2-6x-2$

d).

$\sqrt{48}+\sqrt{15}\ (\frac{2}{\sqrt3}-\frac{4}{\sqrt5})+\sqrt{5-1}=\\\\\sqrt{48}+{\sqrt{15}} (\frac{2\sqrt5-4\sqrt3}{\sqrt{15}})+\sqrt{4}=\\\\\sqrt{48}+2\sqrt5-4\sqrt3+2=4\sqrt3+2\sqrt5-4\sqrt3+2=2+2\sqrt5$

e).

$[(\sqrt2-\sqrt3)^2+\sqrt{24}]*\frac1{\sqrt{50}}=\\\\(2-2\sqrt6-3+2\sqrt6)*\frac1{\sqrt{50}}=-(\frac1{\sqrt{50}})=-\frac{\sqrt{50}}{50}=\frac{5\sqrt2}{50}=\frac{\sqrt2}{10}$