a)2-|x+5|=7
TH1 : 2-|x+5|=7
⇔ x +5 = 2 - 7
⇔ x + 5 = -5
⇔ x = -5 - 5
⇔ x = -10
TH2: 2-|x+5|= -7
⇔ x +5 = 2 - (-7)
⇔ x +5 = 9
⇔ x = 9 - 5
⇔ x = 4
Vậy x ϵ {4;-10}
đề bài ko có còn bày đặt ra hạn ... > . < ...
a)2-|x+5|=7
TH1 : 2-|x+5|=7
⇔ x +5 = 2 - 7
⇔ x + 5 = -5
⇔ x = -5 - 5
⇔ x = -10
TH2: 2-|x+5|= -7
⇔ x +5 = 2 - (-7)
⇔ x +5 = 9
⇔ x = 9 - 5
⇔ x = 4
Vậy x ϵ {4;-10}
đề bài ko có còn bày đặt ra hạn ... > . < ...
\(Tìm\) \(x\)∈\(Z\)\(,\) \(biết\)\(:\)
\(a\)) \(\left(x-20\right)+\left(x-19\right)+\left(x-18\right)+...+99+100=100\)
\(b\)) \(213-x.\left(\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{2020}}\right):\left(1-\dfrac{1}{2^{2020}}\right)=13\)
Bài 1 Tìm x ,y biết
a, 2| 2x -3 | =1
b,7,5 -3 | 5 -2x | = -4,5
c, | 3x-4 | + | 3y +5 |=0
Bài 2 Tìm x biết
a, \(\left|\frac{5}{3}x\right|\) =\(\left|-\frac{1}{6}\right|\)
b, \(\left|\frac{3}{4}x-\frac{3}{4}\right|-\frac{3}{4}=\left|-\frac{3}{4}\right|\)
c, \(\left|x+\frac{3}{5}\right|-\left|x-\frac{7}{3}\right|=0\)
Bài 3 Tìm x biết
a,| x |+| x+2 |=0
b,\(\left|x\left(x^2-\frac{5}{4}\right)\right|=x\)
Bài 1: Tìm x a) \(\frac{1}{7}\cdot\left|x\right|-\frac{4}{5}=\frac{1}{5}\) b) \(\left(\frac{3}{4}-x\right)^3=-27\) c) \(\frac{x-1}{-2}=\frac{-8}{x-1}\) d) \(\left|2x-3\right|+4\cdot\left(-5\right)^2=101\)
Bài 2 : Tìm x, biết :
1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)
2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)
3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)
4) \(\left|x+\frac{2}{3}\right|=0\)
5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)
6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)
7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)
Bài 1:
1. Tính: \(E=1+\frac{1}{2}\left(1+2\right)+\frac{1}{3}\left(1+2+3\right)+\frac{1}{4}\left(1+2+3+4\right)+...+\frac{1}{200}\left(1+2+...+200\right)\)
2. Tìm và tính tổng các số nguyên x thỏa mãn: \(\frac{21}{5}\left|x\right|< 2019\)
3. Tìm x, biết: \(\frac{2^{24}\left(x-3\right)}{\left(3\frac{5}{7}-1,4\right)\left(6\cdot2^{24}-4^{13}\right)}=\left(\frac{5}{3}\right)^2\)
Bài 1 : Tính
1) \(\frac{4}{7}-\frac{1}{14}+\left|\frac{-5}{21}\right|\)
2) \(\left|\frac{-2}{3}\right|-\frac{1}{2}+3\)
3) \(\left|\frac{7}{-4}\right|-\frac{5}{8}+\frac{-2}{3}\)
4) \(\frac{4}{5}+\left|\frac{-3}{2}\right|+\frac{1}{-4}\)
5) \(\left|\frac{-1}{4}\right|-3+\frac{3}{4}\)
6) \(\left|\frac{-1}{3}\right|-\frac{5}{4}+\frac{1}{5}\)
Bài 2 : Tìm x, biết :
1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)
2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)
3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)
4) \(\left|x+\frac{2}{3}\right|=0\)
5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)
6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)
7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)
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E cần gấp lắm ạ, cảm ơn.
Bài 1 : Tính
1) \(\frac{4}{7}-\frac{1}{14}+\left|\frac{-5}{21}\right|\)
2) \(\left|\frac{-2}{3}\right|-\frac{1}{2}+3\)
3) \(\left|\frac{7}{-4}\right|-\frac{5}{8}+\frac{-2}{3}\)
4) \(\frac{4}{5}+\left|\frac{-3}{2}\right|+\frac{1}{-4}\)
5) \(\left|\frac{-1}{4}\right|-3+\frac{3}{4}\)
6) \(\left|\frac{-1}{3}\right|-\frac{5}{4}+\frac{1}{5}\)
Bài 2 : Tìm x, biết :
1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)
2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)
3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)
4) \(\left|x+\frac{2}{3}\right|=0\)
5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)
6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)
7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)
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E đang cần gấp, cảm ơn :)
Tìm x thuộc Z, biết:
a. 1 + \(\left\{-2-[-3+\left(-4+\left|x\right|\right)]\right\}=1-2+[\left(-3-4\right)]\)
b. 34 + (9 - 21) = 3417 - (x + 3417)
c. x - \(\left\{55-[49+\left(-28-x\right)]\right\}=13-\left\{47+[25-\left(32-x\right)]\right\}\)
d. (15 - x) + (x - 12) = 7 - (-8 + x)
e. - 7 + \(\left|x-4\right|\) = - 3
f. 13 - \(|\)x + 5\(|\) = 13
g. \(|\)x + 1\(|\) > 2
h. \(|\)x + 2\(|\) ≤ 5
i. \(|\)x - 10\(|\) - (-12) = 4
Bài 1: Tìm x:
a) \(\left|x+\dfrac{4}{15}\right|-\left|-3,75\right|=-\left|-2,15\right|\)
b) \(\left|\dfrac{5}{3}x\right|=\left|-\dfrac{1}{6}\right|\)
c) \(\left|\dfrac{3}{4}x-\dfrac{3}{4}\right|-\dfrac{3}{4}=\left|-\dfrac{3}{4}\right|\)
Bài 2: Tìm x,y:
a) \(\left|\dfrac{1}{2}-\dfrac{1}{3}+x\right|=\dfrac{1}{4}-\left|y\right|\)
b) \(\left|x-y\right|+\left|y+\dfrac{9}{25}\right|=0\)
Bài 3: Tìm giá trị nhỏ nhất:
a) A= \(\left|x+\dfrac{15}{19}\right|-1\)
b) B= \(\dfrac{1}{2}+\left|x-\dfrac{4}{7}\right|\)
Bài 4: Tìm giá trị lớn nhất:
a) A= 5- \(\left|\dfrac{5}{3}-x\right|\)
b) B= 9-\(\left|x-\dfrac{1}{10}\right|\)