a) \(\dfrac{1}{5}:x=\dfrac{-1}{5}-\dfrac{-4}{5}\)
\(_{_{ }\Rightarrow\dfrac{-1}{5}:x=\dfrac{3}{5}}\)
\(\Rightarrow x=\dfrac{1}{5}:\dfrac{3}{5}\)
\(\Rightarrow x=\dfrac{1}{3}\)
Vậy \(x=\dfrac{1}{3}\)
b) \(-\left(x-2\right)^3=125\)
\(\Rightarrow\left(x-2\right)^3=-125\)
\(\Rightarrow x-2=-5\)
\(\Rightarrow x=-5+2\)
\(\Rightarrow x=-3\)
Vậy x=-3
1.Tính:
\(\left(\dfrac{-2}{3}\right)\)\(\times0.75+1\dfrac{2}{3}\div\left(\dfrac{-4}{9}\right)+\left(\dfrac{-1}{2}\right)^2\)
2.Tìm x:
a)\(\dfrac{3}{4}-\left(x+\dfrac{1}{2}\right)=\dfrac{4}{5}\)
b) \(\left|x-\dfrac{2}{5}\right|+\dfrac{3}{4}=\dfrac{11}{4}\)
3.Tìm n, biết:
a) \(\dfrac{16}{2^n}=2\)
b)\(\dfrac{\left(-3\right)^n}{81}=-27\)
4. Tìm ba số x,y,z biết:
\(\dfrac{x}{2}=\dfrac{y}{3};\dfrac{y}{5}=\dfrac{z}{4}\)và x-y+z= -49
Tìm x, y, z:
a) \(\left|x+\dfrac{19}{5}\right|+\left|y+\dfrac{1890}{1975}\right|+\left|z-2005\right|=0\)
b) \(\left|x+\dfrac{3}{4}\right|+\left|y-\dfrac{1}{5}\right|+\left|x+y+z\right|\) = 0
c) \(\dfrac{16}{2^x}=1\)
d) \(\left(2x-1\right)^3=-27\)
e) \(\left(x-2\right)^2=1\)
f) \(\left(x+\dfrac{1}{2}\right)^2=\dfrac{4}{25}\)
g) \(\left(x-1\right)^2=\left(x-1\right)^6\)
tìm x;y
b \(\left|x-y\right|+\left|y+\dfrac{9}{25}=0\right|\)
c \(\left(\dfrac{1}{2}x-5\right)^{20}+\left(y^2-\dfrac{1}{4}\right)^{10}=0\)
a \(\left|\dfrac{1}{2}-\dfrac{1}{3}+x\right|=\dfrac{-1}{4}-y\)
d \(\left|x\left(x^2-\dfrac{5}{4}\right)\right|=x\) \(\left(x\ge0\right)\)
e \(x^2+\left(y-\dfrac{1}{10}\right)^4=0\)
Bài 1 : Thực hiện phép tính :
\(S=\dfrac{21^2\cdot3^5-4^6\cdot9^2}{\left(2^2\cdot3\right)^6+8^4\cdot3^5}-\dfrac{5^{10}\cdot7^3-25^5\cdot49^2}{\left(125\cdot7\right)^3\cdot5^0\cdot14^3}\).
Bài 2 : Tìm x :
ɑ) \(2^{x-1}+5\cdot2^{x-2}=\dfrac{7}{32}\). b) \(\left|x\left(x^2-\dfrac{5}{4}\right)\right|=x\).
a)\(\dfrac{\left(x+\dfrac{3}{4}\right)\cdot\dfrac{7}{2}-\dfrac{1}{6}}{-\left(\dfrac{4}{5}+\dfrac{1}{3}\right)\cdot\dfrac{1}{2}+1}=2\dfrac{33}{52}\)
b)\(\dfrac{\left(5-\dfrac{2}{7}\right)\cdot\dfrac{7}{9}:\dfrac{3}{5}}{\left(3x-\dfrac{5}{6}\right):\dfrac{1}{7}}=5\dfrac{5}{21}\)
Bài 7: Tìm X
1 tính
a, \(-\dfrac{2}{3}-\left(\dfrac{-2}{5}\right)-\dfrac{7}{10}\)
b, \(\dfrac{-5}{9}.\left(\dfrac{3}{10}-\dfrac{2}{5}\right)\)
c, \(\left(\dfrac{11}{24}:\dfrac{55}{36}\right).\dfrac{10}{3}\)
d, \(\left(\dfrac{1}{2}-1\right).\left(\dfrac{1}{3}-1\right)...\left(\dfrac{1}{2017}-1\right)\)
e,\(\left(\dfrac{2}{3}\right):\left(\dfrac{4}{9}\right)^{10}\)
f,\(\left(\dfrac{1}{7}\right)^7.7^7\)
g, \(\dfrac{\left(125\right)^5}{5^{15}}\)
2 tìm x, biết
a, \(\dfrac{-4}{7}-x=\dfrac{5}{7}\)
b, \(x:\left(\dfrac{-3}{8}\right)=\dfrac{1}{2}\)
c, \(\dfrac{-3}{5}+\dfrac{1}{4}:x=\dfrac{-2}{5}\)
d, \(\left(x-\dfrac{2}{5}\right).\left(x+\dfrac{3}{7}\right)=0\)
e, \(\left(x+1\right)^5=-32\)
f, \(x-\left(1,5-7\right)=0,35\)
3 tìm số tự nhiên n biết
a, \(3^n=81\)
b, \(2^n=16\)
c, \(2.2^n=16\)
d, \(2.8^n=128\)
5 so sánh
a, \(2^{333}\) và \(3^{222}\)
b, \(\left(\dfrac{-1}{16}\right)^{100}\) và \(\left(\dfrac{-1}{2}\right)^{400}\)
tìm x biết
a) \(\dfrac{1}{2}x+2\dfrac{1}{2}=3\dfrac{1}{2}x-\dfrac{3}{4}\)
b) \(\dfrac{2}{3}x-\dfrac{2}{5}=\dfrac{1}{2}x-\dfrac{1}{3}\)
c) \(\dfrac{1}{3}x+\dfrac{2}{5}\left(x+1\right)=0\)
d) \(\dfrac{2}{3}-\dfrac{1}{3}\left(x-\dfrac{3}{2}\right)-\dfrac{1}{2}\left(2x+1\right)=5\)
e) \(\dfrac{x+2015}{5}+\dfrac{x+2016}{4}=\dfrac{x+2017}{3}+\dfrac{x+2018}{2}\)
tìm x,y,z biết
\(\left(x-\dfrac{1}{5}\right).\left(y+\dfrac{1}{2}\right).\left(z-3\right)=0\)
và x+1=y+2=Z+3
Bài 2: Tìm x,y,z biết:
a) \(|\left(-1.1\right)^2\cdot5-1.1\cdot15.5|\cdot x-2=-2^3\cdot\left(-\dfrac{1}{2}\right)^3-\dfrac{1}{2}\)
b) \(3^{x+2}+4\cdot3^{x+1}+3^{x-1}=6^6\)
c) \(3+2^{x-1}=24-[4^2-\left(2^2-1\right)]\)
d) \(x:\left(-3\right)=y:4=z:5\) và \(-2x+7y-3z=171\)
e) \(\dfrac{x-2}{4}=\dfrac{-16}{2-x}\)
g) \(3x+x^2=0\)
h) \(\left(x-\dfrac{1}{2}\right)^5=\dfrac{1}{243}\)
i) \(\dfrac{4+x}{7+y}=\dfrac{4}{7}\) và \(x+y=22\)
Mn giúp e với nha... cảm ơn mn nhiều lắm ạ!!!
( nếu bạn nào có chơi face hãy ghi tên face mình sẽ tặng bạn những ảnh anime đẹp)