Question

решите уравнение 8(x+4)=1/x

Answer 1

8(x+4)=1/x

8x+32=1/x

(8x+32)x=1

(8x+32)x-1=0

8x²+32x-1=0

D=b²-4ac=32²-4*8*(-1)=1056.

x1=(-b+√D)/2a=(-32+√1056)/2=(-8+√66)/2.

x2=(-b-√D)/2a=(-32-√1056)/2=(-8-√66)/2.

Answer 2

Ответ:

$\frac{{ - 8 \pm \sqrt {66} }}{4}$

Пошаговое объяснение:

$8(x + 4) = \displaystyle\frac{1}{x};\\\\8x(x + 4) = 1;\\\\8{x^2} + 32x - 1 = 0;\\\\D = {32^2} - 4 \cdot 8 \cdot ( - 1) = 1024 + 32 = 1056 = {(4\sqrt {66} )^2};\\\\x = \displaystyle\frac{{ - 32 \pm 4\sqrt {66} }}{{16}} = \displaystyle\frac{{ - 8 \pm \sqrt {66} }}{4}.$