Tính 3 trên2x + 3x-3 trên 2x-1 + 2x^2+1 trên 4x^2-2x 22/08/2021 Bởi Everleigh Tính 3 trên2x + 3x-3 trên 2x-1 + 2x^2+1 trên 4x^2-2x
Ta có $\dfrac{3}{2x} + \dfrac{3x-3}{2x-1} + \dfrac{2x^2+1}{4x^2-2x} = \dfrac{3(2x-1)}{2x(2x-1)} + \dfrac{2x(3x-3)}{2x(2x-1)} + \dfrac{2x^2+1}{2x(2x-1)}$ $= \dfrac{6x-3+6x^2-6x + 2x^2 + 1}{2x(2x-1)}$ $= \dfrac{8x^2 -2}{2x(2x-1)}$ $= \dfrac{2(4x^2-1)}{2x(2x-1)}$ $= \dfrac{(2x-1)(2x+1)}{x(2x-1)}$ $= \dfrac{2x+1}{x}$ Bình luận
Ta có
$\dfrac{3}{2x} + \dfrac{3x-3}{2x-1} + \dfrac{2x^2+1}{4x^2-2x} = \dfrac{3(2x-1)}{2x(2x-1)} + \dfrac{2x(3x-3)}{2x(2x-1)} + \dfrac{2x^2+1}{2x(2x-1)}$
$= \dfrac{6x-3+6x^2-6x + 2x^2 + 1}{2x(2x-1)}$
$= \dfrac{8x^2 -2}{2x(2x-1)}$
$= \dfrac{2(4x^2-1)}{2x(2x-1)}$
$= \dfrac{(2x-1)(2x+1)}{x(2x-1)}$
$= \dfrac{2x+1}{x}$