Question

Va rog frumos puteti sa imi rezolvati aceste exercitii, dar putin mai indetaliat

Answer 1

$\it a)\ 3\sqrt a+2\sqrt{4a}-10\sqrt{9a} = 3\sqrt a+2\cdot2\sqrt{a}-10\cdot3\sqrt{a} =\\ \\ =3\sqrt a+4\sqrt{a}-30\sqrt{a} = 7\sqrt a-30\sqrt a = -23\sqrt a$

$\it d)\ \sqrt{27x^3} -2\sqrt{12x^3}+9\sqrt{48x^3}=\sqrt{9\cdot3\cdot x^2\cdot x} -2\sqrt{4\cdot3\cdot x^2\cdot x}+9\sqrt{16\cdot3\cdot x^2\cdot x}=\\ \\ =3x\sqrt{3x} -4x\sqrt{3x}+36x\sqrt{3x} =39x\sqrt{3x}-4x\sqrt{3x} =35\sqrt{3x}$

Answer 2

Răspuns:

b.√x⁴=x²

√16x²=√(4x)²=l4xl=4x pt ca   x≥0

√4x²=√(2x)²= l2xl=2x

expresia devine

4x²+9·4x-10·2x=

4x²+36x-20x=

4x²+16x=dai factorcomun pe 4x

4x(x+4)

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d√27x³-2√12x³+9√48x³=

√9x²·3x-2√4x²·3x+9√16x²·3x=

l3xl√3x-2·l2xl√3x+9·l4xl√3x=

3x√3x-2·2x√3x+9·4x√3x=

3x√3x-4x√3x+36√3x=35√3x

Explicație pas cu pas: