Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\frac{7x+2}{5x+7}=\frac{7x-1}{5x+1}=\frac{7x+2-7x+1}{5x+7-5x-1}=\frac{3}{6}=\frac{1}{2}\)
\(2\left(7x+2\right)=5x+7\)
\(14x-5x=7-4\)
\(9x=3\)
\(\Rightarrow x=3\div9\)
\(\Rightarrow x=\frac{1}{3}\)
nhân chéo ta được:
\(\left(7x+2\right)\left(5x+1\right)=\left(5x+7\right)\left(7x-1\right)\)
\(35x^2+7x+10x+2=35x^2-5x+49x-7\) ( nhân phân phối)
\(35x^2-35x^2+7x+10x-5x+49x=-2-7\)
\(-27x=-9\)
\(x=\frac{-9}{-27}\)
\(x=\frac{1}{3}\)
2 - 13/3 < x < 1 - 2,4
- 7/3 < x < - 7/5
\(-2^1_3< x< -1^2_5\)
x thuộc Z
=> x = - 2
\(\frac{7x+2}{5x+7}=\frac{7x-1}{5x+1}=\frac{7x+2-\left(7x-1\right)}{5x+7-\left(5x+1\right)}=\frac{7x+2-7x+1}{5x+7-5x-1}=\frac{3}{6}=\frac{1}{2}\)
tu \(\frac{7x+2}{5x+7}=\frac{1}{2}=>\left(7x+2\right).2=5x+7=>14x+4=5x+7=>14x-5x=7-4=>9x=3=>x=\frac{3}{9}=\frac{1}{3}\)
vay x=1/3
tick nha
\(\frac{x-1}{42}+\frac{2x-1}{83}+\frac{3x-1}{124}=-3\)
\(< =>\frac{10292.\left(x-1\right)}{432264}+\frac{5208.\left(2x-1\right)}{432264}+\frac{3486.\left(3x-1\right)}{432264}=\frac{-3.432264}{432264}\)
\(< =>10292.\left(x-1\right)+5208.\left(2x-1\right)+3486.\left(3x-1\right)=-1296792\)
\(< =>10292x-10292+10416x-5208+10458x-3486=-1296792\)
\(< =>\left(10292+10416+10458\right)x=-1296792+3486+5208+10292\)
\(< =>31166x=-1277806\)
\(< =>x=\frac{-1277806}{31166}\)
\(< =>x=-41\)
\(\Leftrightarrow\frac{5146x-5146+5208x-2604+5229x-1743}{216132}=-3\)
\(\Leftrightarrow\frac{15583x-9493}{216132}=-3\)
\(\Leftrightarrow15583x=-638903\)
\(\Leftrightarrow x=-41\)
\(\frac{17^2}{x}=\frac{7x^2}{-119}\)
=\(17^2.\left(-119\right)=7x^2.x\)
=\(-34391=7x^3\)
=\(-4913=x^3\)
x=\(\sqrt[3]{-4913}=-17\)