`<=> 2x : 4/5 = 1,6/4`
`<=> 2,5x = 0,4`
`<=> 5/2x = 2/5`
`x = 2/5 : 5/2`
`x = 4/25`
\(\left|2x:\dfrac{4}{5}-\dfrac{1,6}{4}\right|=0\)
Bài 1:
a) |2x - 3| - \(\dfrac{1}{3}\)= 0
b) \(\dfrac{5}{6}-\left|x+\dfrac{1}{4}\right|=\dfrac{1}{4}\)
c) \(\left|2x-1\right|-\left|x+\dfrac{1}{3}\right|=0\)
d) \(3x-\left|x+15\right|=\dfrac{5}{4}\)
Bài 2:
a) A= 1,3 + 2,5
b) B= -4,3 - 13,7 + (-5,7) - 6,3
c) C= 25.(-5).(-0,4).(-0,2)
d) D=|11,4 - 3.4| + |12,4 - 15,5|
2. Tìm x
a. \(\dfrac{4}{5}-3.\left|x\right|=\dfrac{1}{5}\) b. \(4x-\dfrac{1}{2}x+\dfrac{3}{5}x=\dfrac{4}{5}\)
c. (2x-8)(10-5x)=0 d. \(\dfrac{3}{4}+\dfrac{1}{4}\left|2x-1\right|=\dfrac{7}{2}\)
Câu 1: Thực hiện phép tính
a, \(40\dfrac{1}{4}:\dfrac{5}{7}-25\dfrac{1}{4}:\dfrac{5}{7}-\dfrac{1}{2021}\)
b, \(\left|\dfrac{-5}{9}\right|.\sqrt{81}-2021^0.\dfrac{16}{25}\)
Câu 2: Tìm x
\(3\left(x-\dfrac{1}{3}\right)-7\left(x+\dfrac{3}{7}\right)=-2x+\dfrac{1}{3}\)
a\(\dfrac{-3}{4}x+1=\dfrac{5}{6}\)
b \(\left(2x-3\right).\left(x-5\right)=0\)
c \(\dfrac{1}{2}-|x+1|=0,25\)
Tìm x :
1) \(\left(-0,75x+\dfrac{5}{2}\right).\dfrac{4}{7}-\left(-\dfrac{1}{3}\right)=-\dfrac{5}{6}\)
2) \(\left(4x-9\right)\left(2,5+\dfrac{-7}{3}x\right)=0\)
3) \(\left|x-\dfrac{3}{4}\right|-\dfrac{1}{2}=0\)
4)\(\left(\dfrac{3}{5}-\dfrac{2}{3}x\right)^3=\dfrac{-64}{125}\)
a, \(5^6\) : \(5^5\) + \(\left(\dfrac{4}{9}\right)^0\) b,\(\left(\dfrac{3}{7}\right)^{21}\) : \(\left(1-\dfrac{40}{49}\right)^3\) c, 3.\(\left(\dfrac{2}{3}\right)^3\) -\(\left(\dfrac{-52}{3}\right)^0\) +\(\dfrac{4}{9}\)
Mọi người giúp mình với
Chọn câu trả lời đúng \(\left(2x+\dfrac{1}{5}\right)\left(-\dfrac{3}{5}x+\dfrac{4}{7}\right)=0\) thì:
A. x = \(\dfrac{-1}{10}\) hoặc x = \(\dfrac{20}{21}\)
B. x = \(\dfrac{20}{21}\)
C. x = \(-\dfrac{1}{10}\)
D. x = \(-\dfrac{20}{21}\)
a)\(\left(\dfrac{5}{9}-\dfrac{\sqrt{9}}{12}\right):\dfrac{3}{4}+\dfrac{11}{3}:\dfrac{3}{4}\) b)\(\left(0,\left(3\right)+\dfrac{\text{|}-2\text{|}}{3}\right):\dfrac{\sqrt{25}}{4}-\left(2^3+3^2\right)^0\)
\(\left(3-x\right)^3=-\dfrac{27}{64};\left(x-5\right)^3=\dfrac{1}{-27};\left(x-\dfrac{1}{2}\right)^3=\dfrac{27}{8};\left(2x-1\right)^2=\dfrac{1}{4};\left(2-3x\right)^2=\dfrac{9}{4};\left(1-\dfrac{2}{3}\right)^2=\dfrac{4}{9}\)
