Tim x, biet :
a, x - 150 : 75 = 18
b, 41 - ( 2x - 5 ) = 32
c, 180 + 5 ( x - 13 ) = 100
d, 420 - [ 41 - 2x - 5 ] = 40
e, ( x + 1 ) + ( x + 2 ) + ( x + 3) + ,...............+ ( x + 100 = 5150 )
moi nguoi giup minh nha ! cam on ^^
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Tìm x thuoc z:
1) \(26-\left|x+9\right|=-13\)
\(\Leftrightarrow\left|x+9\right|=26-\left(-13\right)\)
\(\Leftrightarrow\left|x+9\right|=39\)
\(\Leftrightarrow\left[{}\begin{matrix}x+9=39\\x+9=-39\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=39-9=30\\x=-39-9=-48\end{matrix}\right.\)
Vậy: \(x\in\left\{30;-48\right\}\)
2) \(\left|x+7\right|-13=25\)
\(\Leftrightarrow\left|x+7\right|=25+13=38\)
\(\Leftrightarrow x+7\in\left\{38;-38\right\}\)
\(\Leftrightarrow x\in\left\{31;-45\right\}\)
Vậy:.................
tim x biet
\(1)123-3.\left(x+4\right)=23\)
\(\Leftrightarrow3\left(x+4\right)=123-23\)
\(\Leftrightarrow3\left(x+4\right)=100\)
\(\Leftrightarrow x+4=\frac{100}{3}\)
\(\Leftrightarrow x=\frac{100}{3}-4=\frac{100-12}{3}=\frac{88}{3}\)
Vậy:................
2) Tương tự
a)13/17 < 15/19
a) 2/3 x X + 3/4 = 3
2/3 x X = 3 - 3/4
2/3 x X = 9/4
X = 9/4 : 2/3
X = 27/8
a. Ta có : \(\frac{13}{17}=\frac{247}{323};\frac{15}{19}=\frac{255}{323}\)
Vì 255 > 247 nên 247/323 < 255/323
Hay \(\frac{13}{17}< \frac{15}{19}\)
b. \(\frac{2}{3}\times x+\frac{3}{4}=3\)
\(\frac{2}{3}\times x=3-\frac{3}{4}\)
\(\frac{2}{3}\times x=\frac{9}{4}\)
\(x=\frac{9}{4}:\frac{2}{3}\)
\(x=\frac{27}{8}\)
c. \(720:\left[41-\left(2\times x-5\right)\right]=120\)
\(\left[41-\left(2\times x-5\right)\right]=720:120\)
\(41-\left(2\times x-5\right)=6\)
\(2\times x-5=35\)
\(2\times x=40\)
\(x=20\)
a: -x+5/9=-1/3
nên x=5/9+1/3=5/9+3/9=8/9
b: \(\Leftrightarrow\dfrac{1}{5}+\dfrac{1}{10}+\dfrac{11}{15}< x< \dfrac{1}{2}+\dfrac{13}{12}+\dfrac{1}{3}\)
=>31/30<x<23/12
mà x là số nguyên
nên \(x\in\varnothing\)
c: x+5/3=1/81
nên x=1/81-135/81=-134/81
a ) (x+1)+...+(x+100)
= (x+x+..+x)+(1+..+100)
=100x + (100+1).100:2
=100x + 5050
=5750
<=> 100x = 5750 - 5050
<=> 100x = 700
=> x = 700 : 100 = 7
b) 720 : [ 41-(2x-5)]= 40
41-(2x-5) = 720 : 40
41-(2x-5) = 18
2x-5 = 41-18= 23
2x = 23+5 = 28
=> x = 28:2 = 14
Chúc Bạn Học Tốt
Nếu sai thì thông cảm ạ
a: =>41-(2x-5)=720:40=18
=>2x-5=23
=>2x=28
=>x=14
b: =>100x+5050=5750
=>100x=700
=>x=7
a: =>41-(2x-5)=720:40=18
=>2x-5=23
=>2x=28
=>x=14
b: =>100x+5050=5750
=>100x=700
=>x=7
a.x-150:75=18 => x-150=18*75=1350 =>. x=1350+150=1500
b.41-(2x-5)=32 => 2x-5=41-32=9 =>2x=9+5=14 =>x=14:2=7
(x+1)+(x+2)+(x+3)+(x+4)+...+(x+100) = 5150
100* x + (1 + 2 + 3 + 4 + ... + 100) = 5150
100* x + 5050 = 5150
100 * x = 100
x = 100 : 100
x = 1