Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(DK:-\frac{1}{3}\le x\le6\)
\(\Leftrightarrow\left(\sqrt{3x+1}-4\right)-\left(\sqrt{6-x}-1\text{ }\right)+\left(3x^2-15x\right)+\left(x-5\right)=0\)
\(\Leftrightarrow\frac{3x+1-16}{\sqrt{3x+1}+4}-\frac{6-x-1}{\sqrt{6-x}+1}+3x\left(x-5\right)+\left(x-5\right)=0\)
\(\Leftrightarrow\frac{3\left(x-5\right)}{\sqrt{3x+1}+4}+\frac{x-5}{\sqrt{6-x}+1}+3x\left(x-5\right)+\left(x-5\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left(\frac{3}{\sqrt{3x+1}+4}+\frac{1}{\sqrt{6-x}+1}+3x+1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=5\left(n\right)\\\frac{3}{\sqrt{3x+1}+4}+\frac{1}{\sqrt{6-x}+1}+3x+1=0\left(l\right)\end{cases}}\)
Vay nghiem cua PT la \(x=5\)
\(Pt\Leftrightarrow\sqrt{3x+1}-4+1-\sqrt{6-x}+3x^2-14x-5=0\)(ĐKXĐ: \(-\frac{1}{3}\le x\le6\))
\(\Leftrightarrow\frac{3x-15}{\sqrt{3x+1}+4}+\frac{x-5}{1+\sqrt{6-x}}+\left(x-5\right)\left(3x+1\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left(\frac{3}{\sqrt{3x+1}+4}+\frac{1}{1+\sqrt{6-x}}+3x+1\right)=0\)
\(\Rightarrow x=5\)(tmđk)
b. Câu hỏi của Lê Đức Anh - Toán lớp 9 - Học toán với OnlineMath
\(-\dfrac{1}{3}\le x\le6\)
\(\sqrt{3x+1}-4-\left(\sqrt{6-x}-1\right)+3x^2-14x-5=0\)
\(\Leftrightarrow\dfrac{3x-15}{\sqrt{3x+1}+4}+\dfrac{x-5}{\sqrt{6-x}+1}+\left(x-5\right)\left(3x+1\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left(\dfrac{3}{\sqrt{3x+1}}+\dfrac{1}{\sqrt{6-x}+1}+3x-1\right)=0\)
do \(x\ge\dfrac{-1}{3}\Rightarrow3x+1\ge0\)
\(\dfrac{3}{\sqrt{3x+1}}+\dfrac{1}{\sqrt{6-x}+1}+3x-1>0\)
\(\Rightarrow x=5\)
\(\frac{-1}{3}\le x\le6\\ \sqrt[]{3x+1}-4-\left(\sqrt[]{6-x}-1\right)+3x^2-14x-5=0\\ \Leftrightarrow\frac{3x-15}{\sqrt[]{3x+1}+4}+\frac{x-5}{\sqrt[]{6-x+1}}+\left(x-5\right)\left(3x+1\right)=0\\ \Leftrightarrow\left(x-5\right)\left(\frac{3}{\sqrt[]{3x+1}}+\frac{1}{\sqrt[]{6-x}+1}+3x-1\right)=0\)
do\(x\ge\frac{-1}{3}\Rightarrow3x+1\ge0\\ \frac{3}{\sqrt[]{3x+1}}+\frac{1}{\sqrt[]{6-x}+1}+3x-1>0\\ \Rightarrow x=5\)
Câu hỏi của Lê Đức Anh - Toán lớp 9 - Học toán với OnlineMath