a: -2x+1<7
=>-2x<6
hay x>-3
b: (x-1)(x-2)>0
=>x-2>0 hoặc x-1<0
=>x>2 hoặc x<1
c: \(\left(x-2\right)^2\left(x+1\right)\left(x-4\right)< 0\)
=>(x+1)(x-4)<0
=>-1<x<4
d: \(\dfrac{x^2\left(x-3\right)}{x-9}< 0\)
\(\Leftrightarrow\dfrac{x-3}{x-9}< 0\)
=>3<x<9
Tìm x, sao cho:
a) \(1-2x< 7\) b) \(\left(x-1\right)\left(x-2\right)>0\) c)\(\left(x-2\right)^2\left(x+1\right)\left(x-4\right)< 0\) d)\(\dfrac{x^2\left(x-3\right)}{x-9}< 0\)
a,\(\left|3x-4\right|+\left|3y+5\right|=0\) b,\(\left|x+\dfrac{19}{5}\right|+\left|y+\dfrac{1890}{1975}\right|+\left|z-2004\right|=0\) c,\(\left|x+\dfrac{9}{2}\right|+\left|y+\dfrac{4}{3}\right|+\left|z+\dfrac{7}{2}\right|\le0\)
d,\(\left|x+\dfrac{3}{4}\right|+\left|y-\dfrac{1}{5}\right|+\left|x+y+z\right|=0\) e,\(\left|x+\dfrac{3}{4}\right|+\left|y-\dfrac{2}{5}\right|+\left|z+\dfrac{1}{2}\right|\le0\)
Giups mình giải bài tìm x,y,z này nhé!!! Cảm ơn nhiều ạ!!!
Bài 1: Thu gọn đơn thức ( a là hằng só )
a) \(1\dfrac{1}{4}x^2y\left(\dfrac{-5}{6}xy\right)^0.\left(-2\dfrac{1}{3}xy\right)\)
b) \(\dfrac{1}{2}x.\dfrac{1}{4}x^2.\dfrac{x^3}{8}.2y.4y^2.x^3\)
c) \(\left(\dfrac{-9}{2}\right)^3.3xy\left(4a^2x^3\right)\left(4\dfrac{1}{3}ay^2\right)\)
d) \(\left(\dfrac{1}{3}xy^2\right)^3\left(\dfrac{-3}{7}x^4y\right)^2\)
a,\(\dfrac{1}{3}\times\left(x-1\right)+\dfrac{2}{5}\times\left(x+1\right)=0\)
b,4x-\(\left(x+\dfrac{1}{2}\right)=2x-\left(\dfrac{1}{2}x-5\right)\)
c,\(\left(x+\dfrac{1}{2}\right)\times\left(x-\dfrac{3}{4}\right)=0\)
Các bn ơi giúp mk với chiều mk đi học rồi !!!!!!!!!!
1. Tìm \(x\) biết:
a. \(\left|x\right|\)= \(x+2\) với \(x+2\) \(\ge\) 0
b. \(\left|1-3x\right|=x-7\) với \(x-7\) \(\ge\) 0
c. \(\left|2x-3\right|+5-x\) với \(x-5\) \(\le\) 0
2. Tìm \(x\) biết:
a. \(\left|x-\dfrac{3}{2}\right|=\left|\dfrac{5}{2}-x\right|\)
b. \(\left|x-1\right|+\left|x-4\right|=3x\)
c. \(\left|x-\dfrac{3}{2}\right|+\left|\dfrac{-5}{3}+x\right|=0\)
d. \(\left|x.\left(x-4\right)\right|=x\)
GIÚP MK VS AI NHANH MK TICK CHO
Tìm x:
\(3\left|x+4\right|-\left|2x+1\right|-5\left|x+3\right|+\left|x-9=5\right|\)
\(\left|x-2\right|+\left|x-3\right|+\left|2x-8\right|=9\\ \left|x+2\right|+\left|x+3\right|+\left|x+1\right|=4\\ \left|x+\dfrac{1}{1.5}\right|+\left|x+\dfrac{1}{5.9}\right|+\left|x+\dfrac{1}{9.13}\right|+...+\left|x+\dfrac{1}{397.401}\right|=101x\)
tìm x,y biết:
a)\(\left|x+\dfrac{4}{15}\right|-\left|3,75\right|=-\left|-2,15\right|\)
b) \(\left|\dfrac{1}{2}-\dfrac{1}{3}+x\right|=-\dfrac{1}{4}-\left(y\right)\)
c)\(\left|x-y\right|+\left|y+\dfrac{9}{25}\right|=0\)
d)\(\left|x-\dfrac{3}{5}\right|< \dfrac{1}{3}\)
e)\(\left|x+\dfrac{11}{2}\right|>\left|-5,5\right|\)
1) Tính
\(A=\dfrac{1}{13}+\dfrac{3}{13.23}+\dfrac{3}{23.33}+...+\dfrac{3}{2003.2013}\)
\(B=\left(\dfrac{1}{2}-1\right).\left(\dfrac{1}{3}-1\right).\left(\dfrac{1}{4}-1\right)....\left(\dfrac{1}{2018}-1\right)\)
2) Tìm x biết:
a) \(x^2-2x-15=0\)
b) \(\dfrac{3}{\left(x+2\right).\left(x+5\right)}+\dfrac{5}{\left(x+5\right).\left(x+10\right)}+\dfrac{7}{\left(x+10\right).\left(x+17\right)}=\dfrac{x+1}{\left(x+2\right).\left(x+17\right)}\)
3) Cho \(\dfrac{a}{b}=\dfrac{d}{c}\) . Chứng minh: \(\dfrac{a^2+d^2}{b^2+c^2}=\dfrac{ad}{bc}\)
4) Cho \(f\left(x\right)=x^{100}-x^{99}+...+x^2-x+1\)
\(g\left(x\right)=-x^{101}+x^{100}-x^{99}+...+x^2-x+1\)
Tính giá trị của hiệu \(f\left(x\right)-g\left(x\right)\) tại x=0,1
5) Cho tam giác ABC có \(\widehat{A}=\ge90\) ; \(M\in AB,N\in AC\)
Chứng minh: BC > MN
6) Cho tam giác ABC, M là trung điểm BC, biết \(\widehat{BAM}>\widehat{CAM}\) . So sánh B và C
Tìm x,y biết:
a)\(\left|x-\dfrac{4}{11}\right|+\left|5+y\right|=0\)
b)\(\left|\dfrac{1}{2}-\dfrac{1}{3}+x\right|=\dfrac{-1}{4}-\left|y\right|\)
c)\(\left|x-y\right|+\left|\dfrac{9}{25}+y\right|=0\)
