\(\dfrac{x+1}{-2}=\dfrac{2x-3}{-5}\Leftrightarrow\left(x+1\right)\left(-5\right)=\left(2x-3\right)\left(-2\right)\)
\(\Leftrightarrow-5x-5=-4x+6\Leftrightarrow-5-6=-4x+5x\)
\(\Leftrightarrow x=-11\) vậy \(x=-11\)
\(\dfrac{x+1}{-2}=\dfrac{2x-3}{-5}\Leftrightarrow\left(x+1\right)\left(-5\right)=\left(2x-3\right)\left(-2\right)\)
\(\Leftrightarrow-5x-5=-4x+6\Leftrightarrow-5-6=-4x+5x\)
\(\Leftrightarrow x=-11\) vậy \(x=-11\)
Tìm x, biết:
1. \(\left(\dfrac{2x}{5}+2\right):\left(-4\right)=-1\dfrac{1}{2}\)
2. x. ( x + 1) = 0
3. 2x - 16 = 40 + x
4. x : \(\dfrac{5}{3}\) + \(\dfrac{1}{3}\) = \(\dfrac{-2}{5}\)
5. 3\(\dfrac{1}{2}\) - \(\dfrac{1}{2}\) x = \(\dfrac{2}{3}\)
6. \(\dfrac{x}{4}=\dfrac{9}{x}\)
7. \(\dfrac{1}{3}+\dfrac{1}{2}:x=\) -0,25
tìm x
a\(\dfrac{5x-3}{3-2x}=\dfrac{2}{3}\)
b\(\left(\dfrac{4}{5}x+\dfrac{2}{3}\right)\div\dfrac{3}{4}=2\)
c\(\dfrac{3}{4}x-\dfrac{1}{3}=\dfrac{3}{5}\)
d\(\dfrac{2}{3}-\dfrac{3}{5}\div x=\dfrac{1}{4}\)
giúp mình nhé
bài 1: tìm x bt:
a\(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)
b, \(5\dfrac{4}{7}:x=13\)
c, (2 và 4/5.x-50) :2/3= 51
d,\(\left(x+\dfrac{1}{2}\right).\left(\dfrac{2}{3}-2x\right)=0\)
e, \(\dfrac{2}{3}-\dfrac{1}{2}x=\dfrac{5}{12}\)
giúp mk nhs!!!!!!!!!!
1: rút gọn rồi tính
\(\left(-\dfrac{72}{40}-\dfrac{144}{60}-2\dfrac{1}{3}\right)\) : \(\left(\dfrac{45}{100}-\dfrac{25}{60}+-\dfrac{75}{25}\right)\)
2: tìm x: \(3\cdot\left(4-x\right)+\left(x+2\right)\cdot\left(1+2x\right)=7\cdot\left(1+x\right)-2x\cdot\left(2-x\right)\)
3: tìm x: \(\dfrac{2\cdot\left(1+x\right)}{3}-\dfrac{5\cdot\left(2-x\right)}{6}=1\dfrac{1}{3}-\dfrac{3\cdot\left(2x+3\right)}{4}-1\dfrac{1}{2}\cdot\left(x+1\right)\)
4: cho a= \(3+3^{2^3}+3^3+3^4+...+3^{360}\)
BT: Tìm x, biết:
a) \(2\dfrac{2}{3}x+3\dfrac{3}{4}x=\dfrac{385}{24}\)
b) \(-2\dfrac{2}{3}:x=1\dfrac{7}{9}:0.8\)
c) \(140\%+\dfrac{5}{3}x+2x=2280\)
d) \(-3\dfrac{1}{3}\cdot\left|x\right|=1\dfrac{1}{2}-2\dfrac{2}{3}\)
Bài 1. Tính giá trị biểu thức
125%.\((\dfrac{-1}{2})^2\):\((1\dfrac{5}{16}-1,5)+2008^0\)
\(\dfrac{2}{3.5}+\dfrac{2}{5.3}+\dfrac{2}{7.9}+\dfrac{2}{9.11}+\dfrac{2}{11.13}+\dfrac{2}{13.15}\)
Bài 2. Tìm x, biết
x:\(3\dfrac{1}{15}=1\dfrac{1}{12}\)
\(\dfrac{3}{4}.x=27\)
\(x.\dfrac{1}{4}=\dfrac{5}{8}.\dfrac{2}{3}\)
\(\left(x+\dfrac{1}{4}\right):\dfrac{3}{7}=\dfrac{1}{6}\)
\(\dfrac{3}{4}-2.|2x-\dfrac{2}{3}|=2\)
\(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{2}\)
Tìm x
a) \(\left|1-x\right|=\dfrac{1}{4}\)
b) \(\dfrac{x+1}{3}=\dfrac{x}{2}\)
c) \(\dfrac{2x}{3}-\dfrac{x}{4}=\dfrac{5}{6}\)
Bài 1 : Tìm x
a) 4\(\dfrac{1}{2}\)x : \(\dfrac{5}{12}\)=0,5 b)1,5+1\(\dfrac{1}{4}\).x= \(\dfrac{2}{3}\) c) 7,5.1\(\dfrac{3}{4}\)=\(6\dfrac{2}{5}\) d)(x - 5):\(\dfrac{1}{3}\)=\(\dfrac{2}{5}\) e) (4,5-2x):\(\dfrac{3}{4}\)=1\(\dfrac{1}{3}\) f) (2,7x - 1\(\dfrac{1}{2}\)x) : \(\dfrac{2}{7}=\dfrac{-21}{7}\)
Bài 2 : tìm a,b biết
\(\dfrac{a}{27}=\dfrac{-5}{9}=\dfrac{-45}{b}\)
thực hiện phép tính( hợp lí nếu có thể)
\(\dfrac{-5}{9}+1\dfrac{5}{9}.\left(\dfrac{3}{4}-\dfrac{2}{5}\right):7^2\)
\(1\dfrac{13}{15}.0,75-\left(\dfrac{104}{195}+25\%\right).\dfrac{24}{47}-3\dfrac{12}{13}:3\)
\(1\dfrac{13}{15}.\left(0,5\right)^2.3+\left(\dfrac{8}{15}-1\dfrac{19}{60}\right):1\dfrac{23}{24}\)
tìm x
\(60\%x+0,4x+x:3=2\)
\(-2x-\dfrac{-3}{5}:\left(0,5\right)^2=-1\dfrac{1}{4}\)
\(\left(\dfrac{2}{3}-x\right):\dfrac{3}{4}=\dfrac{1}{5}\)