\(\left|2x-5\right|+x=2\\ =>\left|2x-5\right|=2-x\)
=> 2x-5=2-x hoặc 2x-5=-(2-x)
* 2x-5=2-x
=>2x+x=5+2
=>3x=7
=>x=7/3
*2x-5=-(2-x)
=>2x-5=-2+x
=>2x-x=5-2
=>x=3
kết luận...
đúng thì V
Tìm STN x biết rằng:
a)\(720:[41-\left(2x-5\right)]=2^3\cdot5\)
b)\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+...+\left(x+100\right)=5+50\)
d)\(\left(x+3\right)^{10}=\left(x-3\right)^{17}\)
Tìm x:
a,\(x^2\) - 9 = 0
b,\(\left(x-3\right)^2-25=0\)
c,\(\left(x-3\right)\left(2x-5\right)=0\)
d,\(\left(x-3\right)\cdot x-2\left(x-3\right)=0\)
e,\(3x\left(x-1\right)-5\left(1-x\right)=0\)
g,\(x^2+6x-7=0\)
h,\(2x^2+5x-7=0\)
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= \(3+3^{2^3}+3^3+3^4+...+3^{360}\)
Tìm x biet
\(\left(2x+1\right)^3=125\)
\(1999^{2x-6}=1\)
\(x^{2002}=x\)
\(3^x+x^2=1\)
\(\left(x-1\right)^2=9\)
\(\left(2x-3\right)^2=81\)
\(x^{197}=x^2\)
\(\left(3x-14\right)^n=1\)
\(5^{2x}.55^x=625\)
Tìm x
\(-12\left(x-5\right)+7\left(3-x\right)=5\)
\(5\left|2x-10\right|=20\)
A=\(\left|2x-4\right|+2009\) có giá trị nhỏ nhất
B=\(2005-\left|x-5\right|\) có giá trị lớn nhất
- Làm ơn giúp đi ạ, cảm ơn
Tìm x
a, \(311-x+82=46+\left(x-21\right)\)
b,\(-\left(x-3+85\right)=\left(x+70-71\right)-5\)
c,\(-2\left(x+6\right)+6\left(x-10\right)=8\)
d,\(\left|x\right|=41\)
e, \(\left|-8\right|.\left|x\right|=\left|-56\right|\)
f,\(3.\left|x-2\right|+2x=19\) với \(x\) \(\ge\) 2
Giúp hộ đi ạ, cảm ơn.
1:rút gọn
\(\dfrac{11\cdot3^{22}\cdot3^7-9^{15}}{\left(2\cdot3^{14}\right)^2}\)
2: tìm x
\(\dfrac{3\cdot\left(x-2\right)}{4}-\dfrac{2\cdot\left(1+2x\right)}{3}=1\dfrac{1}{4}-5\cdot\dfrac{\left(1+3x\right)}{6}-\dfrac{x-2}{12}\)
Bài 1: Phá dấu ngoặc rồi tính:
a)\(\left(a+b+c\right)-\left(a-b+c\right)\)
b)\(\left(4.x+5.y\right)-\left(5.x-4.y-1\right)\)
Bài 2: Chứng minh bất đẳng thức:
a)\(\left(a+b+c+d\right)-\left(a-b-c+d\right)+1=a-\left(a-2b-2c-d\right)+\left(d+1\right)\)
b)\(\left(4x-3y+2\right)-\left(3x-4y+2\right)=\left(2x+2y\right)-\left(x+y\right)\)
tính:
\(\dfrac{2}{5}x\dfrac{1}{3}-\dfrac{2}{15}:\dfrac{1}{5}+\dfrac{3}{5}x\dfrac{1}{3}\)
2)\(\left(3\dfrac{1}{3}+2,5\right):\left(3\dfrac{1}{6}-4\dfrac{1}{5}\right)-\dfrac{11}{31}\)
3)\(\left[6+\left(\dfrac{1}{2^{ }}\right)^3-\left|-\dfrac{1}{2}\right|\right]:\dfrac{3}{12}\)
4)\(\dfrac{18}{37}+\dfrac{8}{24}+\dfrac{19}{37}-1\dfrac{23}{24}+\dfrac{2}{3}\)
5) \(\left(-2\right)^3x\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)
6)\(\left(\dfrac{2}{5}\right)^2+5\dfrac{1}{2}x\left(45-2\right)+\dfrac{23}{-4}\)
7)\(\dfrac{4}{9}-19\dfrac{1}{3}-\dfrac{4}{9}x39\dfrac{1}{3}\)
8)\(\left(-\dfrac{1}{2}\right)^2:\dfrac{1}{4}-2x\left(-\dfrac{1}{2}\right)^2\)
9)\(125\%x\left(-\dfrac{1}{2}\right)^3:\left(1\dfrac{5}{16}-1,5\right)+2008^0\)
giúp mình nha mai mình học rùi 
