Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
chưa học nhưng sẽ cố giải
a,\(3\left(x-2\right)-\left(x-5\right)>21\)
\(< =>3x-6-x+5>21\)
\(< =>2x-1>21\)
\(< =>2x>21+1=22\)
\(< =>x>11\)
b,\(5\left(x+1\right)-7\left(x-3\right)< 10\)
\(< =>5x+5-7x+21< 10\)
\(< =>26-2x< 10< =>2x>16< =>x>8\)
a) 3( x - 2 ) - ( x - 5 ) > 21
<=> 3x - 6 - x + 5 > 21
<=> 2x - 1 > 21
<=> 2x > 20
<=> x > 10
b) 5( x + 1 ) - 7( x - 3 ) < 10
<=> 5x + 5 - 7x + 21 < 10
<=> -2x + 26 < 10
<=> -2x < -16
<=> x > 8
a: =>17x-5x-15-2x-5=0
=>10x-20=0
=>x=2
b: =>\(\dfrac{3x-6-5x-10}{\left(x+2\right)\left(x-2\right)}=\dfrac{11x+23}{\left(x+2\right)\left(x-2\right)}\)
=>11x+23=-2x-16
=>13x=-39
=>x=-3(nhận)
c: =>5x+7>=3x-3
=>2x>=-10
=>x>=-5
d: =>5(3x-1)=-2(x+1)
=>15x-5=-2x-2
=>17x=3
=>x=3/17
e: =>4x^2-1-4x^2-3x-2=0
=>-3x-3=0
=>x=-1
g: =>7x-5-8x+2-7<0
=>-x-10<0
=>x+10>0
=>x>-10
a: =>17x-5x-15-2x-5=0
=>10x-20=0
=>x=2
b: =>\(\dfrac{3x-6-5x-10}{\left(x+2\right)\left(x-2\right)}=\dfrac{11x+23}{\left(x+2\right)\left(x-2\right)}\)
=>11x+23=-2x-16
=>13x=-39
=>x=-3(nhận)
c: =>5x+7>=3x-3
=>2x>=-10
=>x>=-5
d: =>5(3x-1)=-2(x+1)
=>15x-5=-2x-2
=>17x=3
=>x=3/17
e: =>4x^2-1-4x^2-3x-2=0
=>-3x-3=0
=>x=-1
g: =>7x-5-8x+2-7<0
=>-x-10<0
=>x+10>0
=>x>-10
Câu B đây;vừa bị lag
B, \(\frac{x+1}{35}\)+\(\frac{x+3}{33}\)=\(\frac{x+5}{31}\)+\(\frac{x+7}{29}\)
⇔ \(\frac{x+1}{35}\)+1+\(\frac{x+3}{33}\)+1=\(\frac{x+5}{31}\)+1+\(\frac{x+7}{29}\)+1
⇔ \(\frac{x+36}{35}\)+\(\frac{x+36}{33}\)-\(\frac{x+36}{31}\)-\(\frac{x+36}{29}\)=0
⇔ (x+36)(\(\frac{1}{35}\)+\(\frac{1}{33}\)-\(\frac{1}{31}\)-\(\frac{1}{29}\))=0
Mà \(\frac{1}{35}\)+\(\frac{1}{33}\)-\(\frac{1}{31}\)-\(\frac{1}{29}\)<0
⇔ x+36=0
⇔ x=-36
Vậy tập nghiệm của phương trình đã cho là:S={-36}
câu C tương tự nhé
Câu 1 :
a, \(\frac{3\left(2x+1\right)}{4}-\frac{5x+3}{6}=\frac{2x-1}{3}-\frac{3-x}{4}\)
\(\Leftrightarrow\frac{6x+3}{4}+\frac{3-x}{4}=\frac{2x-1}{3}+\frac{5x+3}{6}\)
\(\Leftrightarrow\frac{5x+6}{4}=\frac{9x+1}{6}\Leftrightarrow\frac{30x+36}{24}=\frac{36x+4}{24}\)
Khử mẫu : \(30x+36=36x+4\Leftrightarrow-6x=-32\Leftrightarrow x=\frac{32}{6}=\frac{16}{3}\)
tương tự
\(\frac{19}{4}-\frac{2\left(3x-5\right)}{5}=\frac{3-2x}{10}-\frac{3x-1}{4}\)
\(< =>\frac{19.5}{20}-\frac{8\left(3x-5\right)}{20}=\frac{2\left(3-2x\right)}{20}-\frac{5\left(3x-1\right)}{20}\)
\(< =>95-24x+40=6-4x-15x+5\)
\(< =>-24x+135=-19x+11\)
\(< =>5x=135-11=124\)
\(< =>x=\frac{124}{5}\)
a: \(\dfrac{2x-3}{35}+\dfrac{x\left(x-2\right)}{7}< \dfrac{x^2}{7}-\dfrac{2x-3}{5}\)
\(\Leftrightarrow2x-3+5x\left(x-2\right)< 5x^2-7\left(2x-3\right)\)
\(\Leftrightarrow2x-3+5x^2-10x< 5x^2-14x+21\)
=>-8x-3<-14x+21
=>6x<24
hay x<4
3: \(\dfrac{3x-2}{4}< \dfrac{3x+3}{6}\)
\(\Leftrightarrow3\left(3x-2\right)< 2\left(3x+3\right)\)
=>9x-6<6x+6
=>3x<12
hay x<4
a) Ta có: \(3\left(x-2\right)-\left(x-5\right)>21\)
\(\Leftrightarrow3x-6-x+5>21\)
\(\Leftrightarrow2x-1>21\)
\(\Leftrightarrow2x>22\)
hay x>11
Vậy: S={x|x>11}
b) Ta có: \(5\left(x+1\right)-7\left(x-3\right)< 10\)
\(\Leftrightarrow5x+5-7x+21-10< 0\)
\(\Leftrightarrow-2x+16< 0\)
\(\Leftrightarrow-2x< -16\)
hay x>8
Vậy: S={x|x>8}