Dzịt mẹ t kêu 3/6 ms xuống lấy á

\(PT\Leftrightarrow\left(x-1\right)\left(\sqrt{2x^2+6}-x+2\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=1\left(\text{nhận}\right)\\\sqrt{2x^2+6}=x-2\left(1\right)\end{matrix}\right.\\ \left(1\right)\Leftrightarrow2x^2+6=x^2-4x+4\left(x\ge2\right)\\ \Leftrightarrow x^2+4x+2=0\\ \Rightarrow\left[{}\begin{matrix}x=-2+\sqrt{2}\left(\text{loại}\right)\\x=-2-\sqrt{2}\left(\text{loại}\right)\end{matrix}\right.\)

Vậy \(S=\left\{1\right\}\)

:0

ủa alo? helik?

\(B=\dfrac{3+\dfrac{3}{4}-\dfrac{3}{19}}{\dfrac{5}{2}+\dfrac{5}{8}-\dfrac{5}{38}}\cdot\dfrac{15+\dfrac{15}{17}-\dfrac{5}{48}+\dfrac{15}{34}}{2+\dfrac{3}{17}-\dfrac{1}{72}}+2012\\ B=\dfrac{3\left(1+\dfrac{1}{4}-\dfrac{1}{19}\right)}{\dfrac{5}{2}\left(1+\dfrac{1}{4}-\dfrac{1}{19}\right)}\cdot\dfrac{15-\dfrac{5}{48}+\dfrac{45}{34}}{2+\dfrac{3}{17}-\dfrac{1}{72}}+2012\\ B=\dfrac{3}{\dfrac{5}{2}}\cdot\dfrac{\dfrac{15}{2}\left(2-\dfrac{1}{72}+\dfrac{3}{17}\right)}{2+\dfrac{3}{17}-\dfrac{1}{72}}+2012\\ B=\dfrac{6}{5}\cdot\dfrac{15}{2}+2012=2021\)

Vì \(\left\{{}\begin{matrix}\widehat{BAC}=\widehat{BHA}=90^0\\\widehat{ABC}\text{ chung}\end{matrix}\right.\to\Delta ABC\sim\Delta HBA\left(g.g\right)\)

Hiệu số phần bằng nhau là `5-2=3` phần

Đáy là \(15:3\times5=25\left(m\right)\)

Chiều cao là \(25-15=10\left(m\right)\)

Diện tích là \(25\times10=250\left(m^2\right)\)

Các số cần tìm là `x`

\(\dfrac{1}{7}< x< \dfrac{1}{3}\\ \rightarrow\dfrac{6}{42}< x< \dfrac{14}{42}\\ \to x\in\left\{\dfrac{7}{42};\dfrac{8}{42};\dfrac{9}{42};\dfrac{10}{42};\dfrac{11}{42}\right\}\)