X＋2/x＋3 – 5/x²＋x-6 ＋1/2-x Rút gọn giùm m 29/07/2021 Bởi Sadie X＋2/x＋3 – 5/x²＋x-6 ＋1/2-x Rút gọn giùm m
Đáp án: $\frac{x-4}{x-2}$ Giải thích các bước giải: \(\begin{array}{l} A = \frac{{x + 2}}{{x + 3}} – \frac{5}{{x^2 + x – 6}} + \frac{1}{{2 – x}} \\ Đk:x \ne 2;x \ne – 3 \\ A = \frac{{x + 2}}{{x + 3}} – \frac{5}{{(x – 2)(x + 3)}} – \frac{1}{{x – 2}} \\ = \frac{{(x + 2)(x – 2) – 5 – (x + 3)}}{{(x – 2)(x + 3)}} \\ = \frac{{x^2 – 4 – 5 – x – 3}}{{(x – 2)(x + 3)}} \\ = \frac{{x^2 – x – 12}}{{(x – 2)(x + 3)}} \\ = \frac{{(x – 4)(x + 3)}}{{(x – 2)(x + 3)}} \\ = \frac{{x – 4}}{{x – 2}} \\ \end{array}\) Bình luận
Đáp án:
$\frac{x-4}{x-2}$
Giải thích các bước giải:
\(
\begin{array}{l}
A = \frac{{x + 2}}{{x + 3}} – \frac{5}{{x^2 + x – 6}} + \frac{1}{{2 – x}} \\
Đk:x \ne 2;x \ne – 3 \\
A = \frac{{x + 2}}{{x + 3}} – \frac{5}{{(x – 2)(x + 3)}} – \frac{1}{{x – 2}} \\
= \frac{{(x + 2)(x – 2) – 5 – (x + 3)}}{{(x – 2)(x + 3)}} \\
= \frac{{x^2 – 4 – 5 – x – 3}}{{(x – 2)(x + 3)}} \\
= \frac{{x^2 – x – 12}}{{(x – 2)(x + 3)}} \\
= \frac{{(x – 4)(x + 3)}}{{(x – 2)(x + 3)}} \\
= \frac{{x – 4}}{{x – 2}} \\
\end{array}
\)