nói mau

nyc là ai, nói mau

nyc là ai, nói mau

\(20\%\times x+x:0,2=41,6\\ 0,2\times x+x\times5=41,6\\ x\times\left(0,2+5\right)=41,6\\ x\times5,2=41,6\\ x=41,6:5,2\\ x=8\)

\(a,\dfrac{1}{5}x^2y-10x^2y-\dfrac{1}{5}x^2y=-10x^2y=-10.0,5^2.2=-10.0,25.2=-5\\ b,5x^2y-7xy^2+6x^2y-10x^2y+5xy^2=x^2y-2xy^2=0,5^2.2-2.0,5.2^2=0,25.2-2=0,5-2=-1,5\)

mẹ gọi ko nghe à :V

ai gợi nhỡ kia :V

\(\left|x^2+2x-3\right|< x^2+3\\ \Leftrightarrow\left\{{}\begin{matrix}-x^2-3< x^2+2x-3\\x^2+2x-3< x^2+3\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}2x^2+2x>0\\2x+6< 0\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}\left[{}\begin{matrix}x< -1\\x>0\end{matrix}\right.\\x< -3\end{matrix}\right.\\ \Leftrightarrow x< -3\)

\(18,56+x:3,5=46,18\\x:3,5=46,18-18,56\\ x:3,5=27,62\\ x=27,62\times 3,5\\ x=96,67\)

\(\left(\dfrac{7}{2}-x\right)^2-\dfrac{4}{5}=-\dfrac{4}{25}\\ \Rightarrow\left(\dfrac{7}{2}-x\right)^2=\dfrac{16}{25}\\ \Rightarrow\left[{}\begin{matrix}\dfrac{7}{2}-x=\dfrac{4}{5}\\\dfrac{7}{2}-x=-\dfrac{4}{5}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{27}{10}\\x=\dfrac{43}{10}\end{matrix}\right.\)