Tìm số nguyên x biết:
a)\(9-25=\left(7-x\right)-\left(25+7\right)\)
b)35 - 3 . I x I=5.(23-4)
c)10+2.I x I = 2.(32-1)
Tìm x biết :
a) \(\left[\left(6\frac{3}{5}-3\frac{3}{14}\right).2,5\right]:\left(21-1,25\right)=x:5\frac{5}{6}\)
b) \(\left(4-\frac{3}{4}\right):\left(2\frac{1}{3}-1\frac{1}{9}\right)=31x:\left(45\frac{10}{63}-44\frac{25}{84}\right)\)
c) \(\frac{x-1}{x+5}=\frac{6}{7}\)
d) \(\frac{x^2}{6}=\frac{24}{25}\)
e) \(\frac{x-2}{x-1}=\frac{x+4}{x+7}\)
giúp mình nhé
e)
=> (x-2) . (x+7) = ( x-1 ) . ( x +4)
=> x2 +7x - 2x -14 = x2 - x + 4x - 4
x2 + 5x - 14 = x2 + 3x - 4
=> 5x - 14 = 3x - 4
=> 5x - 3x = 14-4
=> 2x = 10 => x = 10 : 2 => x = 5
c)
=>( x-1) . 7 = ( x + 5 ) . 6
=> 7x - 7 = 6x + 30
=> 7x - 6x= 30 + 7
=> x = 37
a,x=\(\frac{5}{2}\)
b,x=\(\frac{13}{176}\)
c,x=37
d, x=\(\frac{12}{5}\)
e, x=5
Bài 1: Thực hiện phép tính:
a) \(\left(\frac{3}{5}\right)^2-[\frac{1}{3}:3-\sqrt{16}.\left(\frac{1}{2}\right)^2]-\left(10\times12-2014\right)^0\)
b)\(|-\frac{100}{123}|:\left(\frac{3}{4}+\frac{7}{12}\right)+\frac{23}{123}:\left(\frac{9}{5}-\frac{7}{15}\right)\)
c) \(\frac{\left(-5\right)^{32}\times20^{43}}{\left(-8\right)^{29}\times125^{25}}\)
Bài 2: Tìm x biết
a)\(\frac{2}{3}-\left(\frac{3}{4}-x\right)=\sqrt{\frac{1}{9}}\)
b) \(\left(\frac{1}{2}-x\right)^2=\left(-2\right)^2\)
c) \(|3x+\frac{1}{2}|-\frac{2}{3}=1\)
d) \(3^{2x+1}=81\)
Bài 2:
a)
\(\frac{2}{3}-(\frac{3}{4}-x)=\sqrt{\frac{1}{9}}=\frac{1}{3}\)
\(\frac{3}{4}-x=\frac{2}{3}-\frac{1}{3}=\frac{1}{3}\)
\(x=\frac{3}{4}-\frac{1}{3}=\frac{5}{12}\)
b)
\((\frac{1}{2}-x)^2=(-2)^2=2^2\)
\(\Rightarrow \left[\begin{matrix} \frac{1}{2}-x=-2\\ \frac{1}{2}-x=2\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{5}{2}\\ x=\frac{-3}{2}\end{matrix}\right.\)
c)
\(|3x+\frac{1}{2}|-\frac{2}{3}=1\)
\(|3x+\frac{1}{2}|=\frac{2}{3}+1=\frac{5}{3}\)
\(\Rightarrow \left[\begin{matrix} 3x+\frac{1}{2}=\frac{5}{3}\\ 3x+\frac{1}{2}=-\frac{5}{3}\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{7}{18}\\ x=\frac{-13}{18}\end{matrix}\right.\)
d)
\(3^{2x+1}=81=3^4\)
\(\Rightarrow 2x+1=4\Rightarrow x=\frac{3}{2}\)
Bài 1:
a)
\((\frac{3}{5})^2-[\frac{1}{3}:3-\sqrt{16}.(\frac{1}{2})^2]-(10.12-2014)^0\)
\(=\frac{9}{25}-(\frac{1}{9}-1)-1\)
\(=\frac{9}{25}-\frac{1}{9}=\frac{56}{225}\)
b)
\(|-\frac{100}{123}|:(\frac{3}{4}+\frac{7}{12})+\frac{23}{123}:(\frac{9}{5}-\frac{7}{15})\)
\(=\frac{100}{123}:\frac{4}{3}+\frac{23}{123}:\frac{4}{3}=(\frac{100}{123}+\frac{23}{123}):\frac{4}{3}=1:\frac{4}{3}=\frac{3}{4}\)
c)
\(\frac{(-5)^{32}.20^{43}}{(-8)^{29}.125^{25}}=\frac{5^{32}.(2^2.5)^{43}}{(-2)^{3.29}.(5^3)^{25}}=\frac{5^{32}.2^{86}.5^{43}}{-2^{87}.5^{75}}\)
\(=\frac{5^{32+43}.2^{86}}{-2^{87}.5^{75}}=\frac{5^{75}.2^{86}}{-2^{87}.5^{75}}=-\frac{1}{2}\)
Bài 2:
a)
\(\frac{2}{3}-(\frac{3}{4}-x)=\sqrt{\frac{1}{9}}=\frac{1}{3}\)
\(\frac{3}{4}-x=\frac{2}{3}-\frac{1}{3}=\frac{1}{3}\)
\(x=\frac{3}{4}-\frac{1}{3}=\frac{5}{12}\)
b)
\((\frac{1}{2}-x)^2=(-2)^2=2^2\)
\(\Rightarrow \left[\begin{matrix} \frac{1}{2}-x=-2\\ \frac{1}{2}-x=2\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{5}{2}\\ x=\frac{-3}{2}\end{matrix}\right.\)
c)
\(|3x+\frac{1}{2}|-\frac{2}{3}=1\)
\(|3x+\frac{1}{2}|=\frac{2}{3}+1=\frac{5}{3}\)
\(\Rightarrow \left[\begin{matrix} 3x+\frac{1}{2}=\frac{5}{3}\\ 3x+\frac{1}{2}=-\frac{5}{3}\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{7}{18}\\ x=\frac{-13}{18}\end{matrix}\right.\)
d)
\(3^{2x+1}=81=3^4\)
\(\Rightarrow 2x+1=4\Rightarrow x=\frac{3}{2}\)
Bài 1: Tính:
A=\(\left(-2\right).\left(-3\right)-5.\left|-5\right|+125.\left(\dfrac{-1}{5}\right)^2\)
B=\(\left(-3\right).\left|-7\right|-\left(-4\right).\left|5\right|+\dfrac{1}{3}.\left|-9\right|\)
C=\(\left(-2\right)^3.\left|-3\right|-\dfrac{1}{5}.\left|-25\right|-4.\left|-7\right|+\left(-2\right)^2\)
D=\(\left(-6\right).\left|-3\right|+2.\left|-9\right|-7\left|\left(-2\right)^3\right|+8.\left|-7\right|\)
E=\(\left|-3^2\right|.\left|4\right|-\left|7\right|.8-\left|6\right|.\left|-8\right|-\left|12\right|.\left(\dfrac{1}{2}\right)^2\)
Bài 2: Tìm x:
a)\(12-2\left|3x+2\right|=10\)
b)\(2.\left|5-4x\right|+17=\left(-2\right)^3.\left(-4\right)\)
c)\(\left|3x-5\right|+\left(-3\right)^2.2=12.\left|3x+5\right|+117\)
d)\(4.\left|3-2x\right|+\left(-5\right).\left|4-3x\right|-5=-6\)
e)\(\left|2x-7\right|-2^3.\left|2x-7\right|+15=-5.\left|2x-7\right|+3\)
f)\(\left|x+2\right|+\left|x^2-4\right|=0\)
g)\(\left|3x-9\right|+\left|x^2-9\right|=0\)
h)\(\left|2x-1\right|+\left|x^2-\dfrac{1}{4}\right|=0\)
1. A = (-2)(-3) - 5.|-5| + 125.\(\left(-\dfrac{1}{5}\right)^2\)
= 6 - 25 + 125.\(\dfrac{1}{25}\)
= -19 + 5
= -14
@Shine Anna
1. B = (-3).|-7| - (-4).|5| + \(\dfrac{1}{3}.\left|-9\right|\)
= -21 + 20 + 3
= 2
@Shine Anna
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) \(\left|x\left(x^2-\dfrac{5}{4}\right)\right|=x\).
1)Tính giá trị biểu thức:
\(\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{7}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
2)Tìm x biết:
a) \(42+\dfrac{3}{7}.\left|3x-1\right|=12\)
b) \(\left|2x-1\right|=\left|x+2\right|\)
c) \(2.3^x.3^2=18\) với \(x\in N\)
\(\dfrac{\left(13\dfrac{1}{4}-1\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{7}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
\(=\dfrac{1\dfrac{25}{108}.230\dfrac{1}{25}+46\dfrac{3}{4}}{4\dfrac{16}{21}:\left(-1\dfrac{20}{21}\right)}=\dfrac{330\dfrac{1}{25}}{-2\dfrac{18}{41}}=-135,3164\)
Bài 1: Thực hiện phép tính bằng cách hợp lí < nếu có thể >
a, \(\left(-1,5\right).\left(1+\frac{2}{3}\right)+1,4.\frac{15}{49}-\left(\frac{4}{5}+\frac{2}{3}\right):2\frac{1}{5}\)
b, \(\frac{7}{5}+\frac{4}{5}\left(\frac{5}{8}-\frac{7}{4}\right)+2014^0\)
c, \(1\frac{3}{25}+\frac{17}{19}-\frac{3}{25}+0,9+\frac{2}{19}\)
d, \(-\frac{5}{9}.\frac{6}{13}+\frac{-5}{9}.\frac{7}{23}+\frac{5}{23}:\frac{9}{7}\)
Bài 2: Tìm x, biết
a, 20%x + 0,4x = 4,5
b, \(\left(3\frac{1}{2}-2\left|x-1\right|\right).2\frac{2}{3}=5\frac{1}{3}\)
HELP MEEEEE
Bài 1:
d)
= \(\frac{-5}{9}\left(\frac{6}{13}+\frac{7}{13}\right)+\frac{5}{23}.\frac{7}{9}\)
= \(\frac{-5}{9}.1+\frac{35}{207}\)
= \(\frac{-80}{207}\)
Bài 2:
a) 20%x + 0,4x = 4,5
x( 20% + 0,4 ) = 4,5
x. 0,6 = 4,5
x = 4,5 : 0,6
x = 7,5
Bài 1: Thực hiện phép tính bằng cách hợp lí ( nếu có thể )
a, \(\left(-1,5\right).\left(1+\frac{2}{3}\right)+1,4.\frac{15}{49}-\left(\frac{4}{5}+\frac{2}{3}\right):2\frac{1}{5}\)
b, \(\frac{7}{5}+\frac{4}{5}\left(\frac{5}{8}-\frac{7}{4}\right)+2014^0\)
c, \(1\frac{3}{25}+\frac{17}{19}-\frac{3}{25}+0,9+\frac{2}{19}\)
d, \(-\frac{5}{9}.\frac{6}{13}+\frac{-5}{9}.\frac{7}{23}+\frac{5}{23}:\frac{9}{7}\)
Bài 2: Tìm x, biết:
a, 20%x + 0,4x = 4,5
b, \(\left(3\frac{1}{2}-2\left|x-1\right|\right).2\frac{2}{3}=5\frac{1}{3}\)
HELP ME!
Tìm x biết:
a, \(\dfrac{3}{5}:x+\dfrac{1}{5}=\dfrac{11}{25}\)
b, \(2\left(x-\dfrac{1}{3}\right)-1\dfrac{2}{3}=\dfrac{-23}{15}\)
c, \(\left|x+1\right|-\dfrac{1}{7}=\dfrac{1}{3}\)
d, \(\dfrac{x+1}{3}=\dfrac{2x-1}{5}\)
a/ => \(\dfrac{3}{5}.\dfrac{1}{x}=\dfrac{6}{25}\)
=> \(\dfrac{1}{x}=\dfrac{2}{5}\)
=> x = 5/2
b/ \(\Rightarrow2\left(x-\dfrac{1}{3}\right)=\dfrac{2}{15}\)
=> \(x-\dfrac{1}{3}=\dfrac{1}{15}\)
=> \(x=\dfrac{2}{5}\)
c/ => | x + 1| = 10/21
=> \(\left[{}\begin{matrix}x=-\dfrac{11}{21}\\x=-\dfrac{31}{21}\end{matrix}\right.\)
d/ => \(5x+5=6x-3\)
=> x = 8
Bài 1 :
a) Tính B = \(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.35}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.\left(\sqrt{196}\right)^3}\)
b)Tìm x biết : \(\left|x-\dfrac{1}{3}\right|+\dfrac{4}{5}=\left|-3,2+\sqrt{\dfrac{4}{25}}\right|\)
c)Tính \(\left|3x+1\right|>4\)
Ta có: \(\left|x-\dfrac{1}{3}\right|\)+0,8 = \(\left|-3,2+0,4\right|\)
---> \(\left|x-\dfrac{1}{3}\right|\)+0,8 =2,8 ---> \(\left|x-\dfrac{1}{3}\right|\)= 2,8-0,8=2 --> TH1: x-\(\dfrac{1}{3}\) = 2 --> x= 2+ \(\dfrac{1}{3}\)= \(\dfrac{7}{3}\) TH2: x-\(\dfrac{1}{3}\) = -2---> x= -2+\(\dfrac{1}{3}\)=\(\dfrac{-5}{3}\) Vạy x =\(\dfrac{-5}{3}\) hoặc x= \(\dfrac{7}{3}\) Tick cho mik nha!!