a) \(\dfrac{3}{5}\) . x = \(\dfrac{21}{10}\)
x = \(\dfrac{21}{10}\) : \(\dfrac{3}{5}\)
x = \(\dfrac{21}{10}\) . \(\dfrac{5}{3}\)
x = \(\dfrac{105}{30}\)
x = \(\dfrac{7}{2}\)
b) \(\dfrac{x}{20}\) = \(\dfrac{4}{5}\)
\(\dfrac{x}{20}\) = \(\dfrac{16}{20}\)
=> x = 16
a) Tìm tập hợp các số nguyên x, biết rằng\(4\dfrac{5}{9}:2\dfrac{5}{18}-7< x< \left(3\dfrac{1}{5}:3,2+4,5.1\dfrac{31}{45}\right):\left(-21\dfrac{1}{2}\right)\)
b) tìm x, biết \(\left|x+\dfrac{1}{2}\right|+\left|x+\dfrac{1}{6}\right|+\left|x+\dfrac{1}{12}\right|+\left|x+\dfrac{1}{20}\right|+....+\left|x+\dfrac{1}{110}\right|-11x\)
c)Tính gt biểu thức \(C=2x^3-5y^3+2015\) tại x,y thỏa mãn \(\left|x-1\right|+\left(y+2\right)^{20}=0\)
1+Tìm x thuộc N biết \(\left(x-3\right)^6=\left(x-3\right)^7\)
+Tìm x biết
a,\(|2\dfrac{1}{5}-x|+|x-\dfrac{1}{5}|+8\dfrac{1}{5}=1,2\)b, B=\(|x+1|+|3x-4|+|x-1|+5\)
2.Tìm 3 số x,y,z biết
6x=4x=3z và 2x + 3y -5z = -21
3, Độ dài 3 cạnh của 1 tam giác tỉ lệ vs 2,3,4. Ba chiều cao tương ứng vs 3 cạnh tỉ lệ vs 3 số nào
4, Tìm phân số có tử số bằng 7, lớn hơn \(\dfrac{10}{13}\) và nhỏ hơn \(\dfrac{10}{11}\)
5,A=\(|\dfrac{4}{9}-\dfrac{2}{4}|+|0,\left(4\right)+\dfrac{\dfrac{1}{3}-\dfrac{2}{5}-\dfrac{3}{7}}{\dfrac{2}{3}-\dfrac{4}{5}-\dfrac{6}{7}}|\)
Tim x, biet:
a, \(\dfrac{x+1}{5}+\dfrac{x+1}{6}=\dfrac{x+1}{7}+\dfrac{x+1}{8}\)
b, \(\dfrac{x-1}{2009}+\dfrac{x-2}{2008}=\dfrac{x-3}{2007}+\dfrac{x-4}{2006}\)
c, \(\dfrac{3}{\left(x+2\right)\left(x+5\right)}+\dfrac{5}{\left(x+5\right)\left(x+10\right)}+\dfrac{7}{\left(x+10\right)\left(x+17\right)}\)\(=\dfrac{x}{\left(x+2\right)\left(x+17\right)}\)
d, \(\dfrac{2}{\left(x-1\right)\left(x-3\right)}+\dfrac{5}{\left(x-3\right)\left(x-8\right)}+\dfrac{12}{\left(x-8\right)\left(x-20\right)}-\dfrac{1}{x-20}=\dfrac{-3}{4}\)
Help me!!!!!!!!!!
Can gap lam. Ai lam duoc cau no thi lam nha. Cam on nhieu truoc!!!!!!!!!!!!
Tìm x :
a) \(3^{x+1}+2x.3^x-18x-27=0\)
b) \(\dfrac{1}{2}\left|2x+5\right|-\dfrac{5}{4}\left|4x+10\right|+\dfrac{7}{3}\left|-20-8x\right|=\dfrac{1}{6}\)
1. tìm x
a.\(\dfrac{1}{5}+x=\dfrac{13}{30}\)
b.\(\dfrac{1}{6}-x=\dfrac{5}{12}\)
c. \(x.\left(\dfrac{-1^{ }}{2}\right)^2=\dfrac{1}{16}\)
d. \(x:\dfrac{7}{11}=\dfrac{9}{33}\)
e. \(\dfrac{3}{5}.x=\dfrac{-21}{10}\)
Bài 1 : tìm x
a) \(\dfrac{2012-x}{25}+\dfrac{2053-x}{23}+\dfrac{2070-x}{21}+\dfrac{2083-x}{19}-10=0\\ \)
b) \(x+\dfrac{13}{12}+\dfrac{21}{20}+\dfrac{31}{30}+\dfrac{43}{42}+\dfrac{57}{56}+\dfrac{73}{72}+\dfrac{91}{90}=0\)
Tìm x,y,z trong dãy tỉ số bằng nhau
1)\(\dfrac{3x}{8}=\dfrac{3y}{64}=\dfrac{3z}{216}\)và \(2x^2+2y^2.z^2=1\)
2) \(\dfrac{2x+1}{5}=\dfrac{4y-5}{9}=\dfrac{2x+4y-4}{7x}\)
3) \(\dfrac{x^3+y^3}{6}=\dfrac{x^3-2y^3}{4}\)và x6 . y6 =14
4) \(\dfrac{x+4}{6}=\dfrac{3y-1}{8}=\dfrac{3y-x-5}{x}\)
5) \(\dfrac{3}{x-1}=\dfrac{4}{y-2}=\dfrac{5}{z-3}\)và x.y.z=192
6)\(\dfrac{x-y}{3}=\dfrac{x+y}{13}=\dfrac{x.y}{200}\)
7)\(\dfrac{x+1}{2}=\dfrac{y-1}{3}=\dfrac{z+2}{4}=\dfrac{x+y+z+2}{2x+5}\)
8) \(\dfrac{15}{x-9}=\dfrac{20}{y-12}=\dfrac{40}{z-24}\)và x.y = 1200
9)\(\dfrac{40}{x-30}=\dfrac{20}{y-15}=\dfrac{28}{z-21}\) và x.y.z = 22400
10)15x = -10y =6z và x.y.z = -30000
11) Cho\(\dfrac{x+1}{3}=\dfrac{y-2}{5}=\dfrac{2z+14}{9}\)và x+z=y
12) Cho \(\dfrac{x}{3}=\dfrac{y}{4}\)và \(\dfrac{y}{5}=\dfrac{z}{6}\).Tính M=\(\dfrac{2x+3y+4z}{3x+4y+5z}\)
1.Tìm x, biết.
a, \(|x|\) + x = \(\dfrac{1}{3}\)
b, \(|x+2|\) = x
c, \(\dfrac{2}{\left(x-1\right)\left(x-3\right)}\) + \(\dfrac{5}{\left(x-3\right)\left(x-8\right)}\) + \(\dfrac{12}{\left(x-8\right)\left(x-20\right)}\) - \(\dfrac{1}{x-20}\) = \(\dfrac{-3}{4}\)
d, \(\dfrac{3}{\left(x+2\right)\left(x+5\right)}\) + \(\dfrac{5}{\left(x+5\right)\left(x+10\right)}\) + \(\dfrac{7}{\left(x+10\right)\left(x+17\right)}\) = \(\dfrac{x}{\left(x+2\right)\left(x+17\right)}\)
e, \(\dfrac{x-1}{2009}\) + \(\dfrac{x-2}{2008}\) = \(\dfrac{x-3}{20007}\) + \(\dfrac{x-4}{2006}\)
1 tìm x
a,\(\dfrac{1}{4}x-\left|-\dfrac{3}{10}\right|\)
\(\left(\dfrac{2}{5}-\dfrac{7}{10}x\right):1\dfrac{2}{3}=\dfrac{-3}{4}\)
\(\dfrac{7}{16}:\left(\dfrac{x}{4}+\dfrac{9}{2}\right)-1\dfrac{5}{6}=0\)