Toán Thực hiện phép tính : 04/12/2021 By Kinsley Thực hiện phép tính : 2/x-2 + 4/x+2 + 5x – 6 / 4 – x^2
MTC: ( x-2)( x+2)= x^2-4 = 2. (x+2) / (x-2)(x+2) + 4. ( x-2) / ( x+2)( x-2) + -(5x-6) / x^2-4 = 2x+4 + 4x-8 – 5x+6 / (x+2)(x-2) = x +2 / (x+2)(x-2) = 1/ x-2 CHÚC BẠN THI TỐT Trả lời
Đáp án: $\dfrac{1}{x-2}$ Giải thích các bước giải: $\dfrac{2}{x-2}+\dfrac{4}{x+2}+\dfrac{5x-6}{4-x^2}$ $=\dfrac{2}{x-2}+\dfrac{4}{x+2}+\dfrac{-(5x-6)}{(x-2)(x+2)}$ $=\dfrac{2.(x+2)}{(x+2)(x-2)}+\dfrac{4.(x-2)}{(x+2)(x-2)}+\dfrac{-(5x-6)}{(x-2)(x+2)}$ $=\dfrac{2x+4+4x-8-5x+6}{(x+2)(x-2)}$ $=\dfrac{x+2}{(x-2)(x+2)}$ $=\dfrac{1}{x-2}$ Trả lời
MTC: ( x-2)( x+2)= x^2-4
= 2. (x+2) / (x-2)(x+2) + 4. ( x-2) / ( x+2)( x-2) + -(5x-6) / x^2-4
= 2x+4 + 4x-8 – 5x+6 / (x+2)(x-2)
= x +2 / (x+2)(x-2)
= 1/ x-2
CHÚC BẠN THI TỐT
Đáp án: $\dfrac{1}{x-2}$
Giải thích các bước giải:
$\dfrac{2}{x-2}+\dfrac{4}{x+2}+\dfrac{5x-6}{4-x^2}$
$=\dfrac{2}{x-2}+\dfrac{4}{x+2}+\dfrac{-(5x-6)}{(x-2)(x+2)}$
$=\dfrac{2.(x+2)}{(x+2)(x-2)}+\dfrac{4.(x-2)}{(x+2)(x-2)}+\dfrac{-(5x-6)}{(x-2)(x+2)}$
$=\dfrac{2x+4+4x-8-5x+6}{(x+2)(x-2)}$
$=\dfrac{x+2}{(x-2)(x+2)}$
$=\dfrac{1}{x-2}$