Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\left(3x-1,5\right).\left(\frac{-1}{2}x+5\right)=0\)
\(\Leftrightarrow-\frac{3}{2}x^2+15x+\frac{3}{4}x-\frac{15}{2}=0\)
\(\Leftrightarrow-\frac{3}{2}x^2+\frac{63}{4}x-\frac{15}{2}=0\)
\(\Leftrightarrow-6x^2+63x-30=0\)
\(\Leftrightarrow2x^2-21x+10=0\)
\(\Leftrightarrow2x^2-20x-x+10=0\)
\(\Leftrightarrow2x\left(x-10\right)-\left(x-10\right)=0\)
\(\Leftrightarrow\left(x-10\right)\left(2x-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-10=0\\2x-1=0\end{cases}}\) \(\orbr{\begin{cases}x=10\\x=\frac{1}{2}\end{cases}}\)
#Chúc bạn học tốt!
\(\frac{1}{2}.\left(x-\frac{2}{3}\right)-20\%.\left(3x-1,5\right)=0,4\)
\(\Rightarrow\frac{1}{2}.\left(x-\frac{2}{3}\right)-\frac{1}{5}.\left(3x-\frac{3}{2}\right)=\frac{2}{5}\)
\(\Rightarrow\frac{1}{2}.x-\frac{1}{3}-\frac{3}{5}x-\frac{3}{10}=\frac{2}{5}\)
\(\Rightarrow\left(\frac{1}{2}-\frac{3}{5}\right).x=\frac{2}{5}+\frac{3}{10}+\frac{1}{3}\)
\(\Rightarrow\frac{-1}{10}.x=\frac{31}{30}\)
\(\Rightarrow x=\frac{31}{30}:\frac{-1}{10}\)
\(\Rightarrow x=-\frac{31}{3}\)
P/s : Tính theo cách này đúng nhưng sao mk thử lại sai, có j sai trong câu trl mong cacau giúp đỡ :v
\(\frac{1}{2}\left[x-\frac{2}{3}\right]-20\%\left[3x-\frac{1}{5}\right]=0,4\)
\(\Rightarrow\frac{1}{2}x-\frac{1}{3}-\frac{20}{100}\left[3x-\frac{1}{5}\right]=0,4\)
\(\Rightarrow\frac{1}{2}x-\frac{1}{3}-\frac{1}{5}\left[3x-\frac{1}{5}\right]=0,4\)
\(\Rightarrow\frac{1}{2}x-\frac{1}{3}-\frac{3x}{5}-\frac{1}{25}=0,4\)
Làm nốt :v
1) 3x = 45 + 15 = 60
x = 60 : 3 = 20
2) 5x = 50 - 35 = 15
x = 15 : 5 = 3
3) (2x - 5) + 17 = 6
2x - 5 = 6 - 17
2x - 5 = -11
2x = -11 + 5
2x = -6
x = -6 : 2 = -3
4) 10 - 2(4 -3x) = -4
2(4 - 3x) = -4 - 10 = -14
4 - 3x = -14 : 2 = -7
3x = -7 - 4 = -18
x = -18 : 3 = -6
\(\left\{{}\begin{matrix}\left\{{}\begin{matrix}3x-15=45\Leftrightarrow3x=60\Leftrightarrow x=20\\35-5x=50\Leftrightarrow5x=-15\Leftrightarrow x=-3\end{matrix}\right.\\\left\{{}\begin{matrix}\left(2x-5\right)+17=6\Leftrightarrow2x+5=-11\Leftrightarrow2x=-16\Leftrightarrow x=-8\\10-2\left(4-3x\right)=-4\Leftrightarrow8-6x=14\Leftrightarrow6x=-6\Leftrightarrow x=-1\end{matrix}\right.\\\left\{{}\begin{matrix}-12+3\left(-x+7\right)=-18\Leftrightarrow-3x+21=-6\Leftrightarrow-3x=-27\Leftrightarrow x=9\\24:\left(3x-2\right)=-3\Leftrightarrow3x-2=-8\Leftrightarrow3x=-6\Leftrightarrow x=-2\end{matrix}\right.\\-45:5\left(-3-2x\right)=3\Leftrightarrow-15-10x=-15\Leftrightarrow10x=0\Leftrightarrow x=0\end{matrix}\right.\)
3x . 1,5 = 45
\(\Rightarrow\)3x = 45 : 1,5 = 30
\(\Rightarrow\)x = 30 : 3 = 10