\(B=-\left(\left|2x+1\right|+\frac{1}{5}\right)=-\left|2x+1\right|-\frac{1}{5}\)
Vi: \(-\left|2x+1\right|\le0\)
=> \(-\left|2x+1\right|-\frac{1}{5}\le-\frac{1}{5}\)
vậy GTLN của B là \(-\frac{1}{5}\)khi \(x=-\frac{1}{2}\)
Tìm x :
\(\frac{7^{x+2}+7^{x+1}+7^x}{57}=\frac{5^{2x}+5^{2x+1}+5^{2x+3}}{131}\)
Tìm x :
\(\frac{\left(7^{x+2}+7^{x+1}+7^x\right)^{57}}{57}=\frac{5^{2x}+5^{2x+1}+5^{2x+3}}{131}\)
Tìm x;y
\(\frac{x+y}{2z}=\frac{y+z-1}{2x}=\frac{z+x+1}{2y}=\frac{5}{x+y+z}\)
bài 14: Tìm x biết:
a/ \(-\frac{4}{5}-x=2,25\)
b/ \(\left(\frac{2x}{5}-1\right):\left(-5\right)=\frac{1}{7}\)
Tìm x biết
\(\frac{2}{3}+x=\frac{-4}{5}\)\(\frac{2}{5}-x=\frac{-1}{3}\)\(1-\frac{x}{3}=1\frac{1}{2}\)\(1-\left(\frac{2x}{3}+2\right)=-1\frac{1}{3}\)BT 1 TÌM X
A, \(\frac{3}{4}x+1=2\)
b, \(\frac{2}{3}+\frac{1}{3}:x=-1\)
c , |2x-1|=5
tìm x biết :
a) \(\left(x+\frac{1}{2}\right).\left(\frac{2}{3}-2x\right)=0\)
b) \(\left(x.6\frac{2}{7}+\frac{3}{7}\right).2\frac{1}{5}-\frac{3}{7}=-2\)
c) \(x.3\frac{1}{4}+\left(-\frac{7}{6}\right).x-1\frac{2}{3}=\frac{5}{12}\)
d) \(5\frac{8}{17}:x+\left(-\frac{4}{17}\right):x+3\frac{1}{7}:17\frac{1}{3}=\frac{4}{11}\)
e) \(\frac{17}{2}-\left|2x-\frac{3}{4}\right|=-\frac{7}{4}\)
Bài 14 : Tìm x biết :
e) \(\frac{-2}{3}-\frac{1}{3}\left(2x-5\right)=\frac{3}{2}\) g) \(\frac{2}{5}x+\frac{1}{2}=\frac{-3}{4}\) h) \(\frac{1}{3}x-8=\frac{1}{2}\) i) \(x-\frac{1}{4}=\frac{5}{8}.\frac{2}{3}\)
tìm x biết :
a) \(\left(x+\frac{1}{5}\right)^2+\frac{17}{25}=\frac{26}{25}\)
b) \(-1\frac{5}{27}-\left(3x-\frac{7}{9}\right)^3=-\frac{24}{27}\)
c) \(\left(x+\frac{1}{2}\right).\left(\frac{2}{3}-2x\right)=0\)