Question

Упростите выражение 12х/2-х/1-(2-х/2х) и найдете его значение при х=2/7 ​

Answer 1

$\dfrac{12x}2-\dfrac{x}{1-\bigg(2-\dfrac{x}{2x}\bigg)}=6x-\dfrac{x}{1-2+\dfrac{x}{2x}}=6x-\dfrac{x}{-1+\dfrac{x}{2x}}=6x-\dfrac{x}{\dfrac{-2x+x}{2x}}=\\\\$

$6x-\dfrac{x}{\dfrac{-2x+x}{2x}}=6x-\dfrac{2x^2}{-x}=\dfrac{-6x^2-2x^2}{-x}=\dfrac{-8x^2}{-x}=\dfrac{8x^2}x=8x$

$x=\dfrac27$

$8\cdot\dfrac27=\dfrac{16}7$