Tìm X bt:
-7/8+2/3:X=3/5×-5/12
Tìm số hữu tỉ x bt
\(5-1\frac{1}{3}< x+\frac{1}{5}< 12\frac{2}{7}-3\frac{3}{8}\)
1: =>5(2x+6)=40
=>2x+6=8
=>2x=2
=>x=1
2: =>12-(x+3)=256:64=4
=>(x+3)=8
=>x=5
3: =>2x-1=3 hoặc 2x-1=-3
=>x=2 hoặc x=-1
4: \(\Leftrightarrow3^{x+2017}=3^{2015}\)
=>x+2017=2015
=>x=-2
1: =>5(2x+6)=40
=>2x+6=8
=>2x=2
=>x=1
2: =>12-(x+3)=256:64=4
=>(x+3)=8
=>x=5
3: =>2x-1=3 hoặc 2x-1=-3
=>x=2 hoặc x=-1
4:
=>x+2017=2015
=>x=-2
tìm x bt a) 1/2-(3/4-5/6)=1-x b)1/4-x=1/3-1/5 c)5/3-3/4+x=7/12 d)1/4-(1/3-x+5/12)=3-(7/0-1/2 giúp mình nhé
a) 1/2 - (3/4 - 5/6)
<=> 1/2 - (3/4 - 5/6) + x = 1 - x + x
<=> x + 7/12 = 1
<=> x = 1 - 7/12
<=> x = 5/12
=> x = 5/12
b) 1/4 - x = 1/3 - 1/5
<=> 1/4 - x = 5/15 - 3/15
<=> 1/4 - x = 2/15
<=> x = 2/15 - 1/4
<=> x = 7/60
=> x = 7/60
c) 5/3 - 3/4 + x = 7/12
<=> 20/12 - 9/12 + x = 7/12
<=> 11/12 + x = 7/12
<=> x = 7/12 - 11/12
<=> x = -1/3 (sau khi rút gọn)
=> x = -1/3
4) tìm số tự nhiên bt rằng
a) 4^11*25^11< 2^n*5^n < 20^12 * 5^12
b)4^5+4^5+4^5+4^5/3^5+3^5+3^5* 6^5+6^5+6^5+6^5+6^5+6^5/2^5+2^2=2n
5) Tìm x bt: x*(6-x)2003=(6-x)2003
6) Tìm x và y bt: (3x-5)^100+(2y+1)^200< 0
7)Tìm hai số tự nhiên m,n bt: 2m+2n=2m+n
8) Tìm các số nguyên x và y sao chp: (x+2)2+2(y-3)2<3
nhanh cái nào hehe
Tìm x biết :
1/-5 +(-3+12-x)=7-(2-8)
2/8-(7-x+3)=-|-7+2|-(-9)
3/-(12-5+9-x)=3-|5-8+2|
4/-(-3-x+8)-(-3+5)=|5-8|
5/-|5-8|-(4-x+5)=4+|3-9|
mình đang cần gấp câu trả lời ,bạn nào giải được nhanh k luôn ,hứa đấy
1) -5+(-3+12-x)=7-(2-8)
=>-5+(9-x)=7-(-6)
=>-5+9-x=13
=>x=9-5-13=-9
2) 8-(7-x+3)=-|-7+2|-(-9)
=>8-(10-x)=-|-5|+9
=>8-10+x=-5+9
=>x=-5+9-8+10=6
3)-(12-5+9-x)=3-|5-8+2|
=>-(16-x)=3-|-1|
=>-16+x=3-1
=>x=3-1+16=18
4)-(-3-x+8)-(-3+5)=|5-8|
=>-(5-x)-2=|-3|
=>-5+x-2=3
=>x=3+5+2=10
5)-|5-8|-(4-x+5)=4+|3-9|
=>-|-3|-(9-x)=4+|-6|
=>-3-9+x=4+6
=>x=4+6+3+9=22
Tìm x , bt : [12/25 . ( 0.75 + 7/4 ) - 1 ] x = [1 và 2/5 - 3/25 . ( 10,6 - 3/5 )]
Ai giúp mik với ạ Tìm x bt a) -7×(5-x)-2×(x+3)=12
\(-7\left(5-x\right)-2\left(x+3\right)=12\\ \Leftrightarrow-35+7x-2x-6-12=0\\ \Leftrightarrow5x-53=0\\ \Leftrightarrow5x=53\\ \Leftrightarrow x=\dfrac{53}{5}\)
Tìm x biết:
1) -5 + (-3 +12-x) = 7-(2-8)
2) 8- (7-x+3) = - |-7+2| - (-9)
3) -(12-5+9-x) = 3-| 5-8+2|
1/4.12/13+1/4.1/13-12%
*Tìm x bt
a, |2/5:x |=1/4
c,x/24=-1/3-1/8
d, 3/x+3=-7/21
1/4.12/13+1/4.1/13-3/25
1/4.(12/13+1/13)-3/25
1/4.1-3/25
1/4-3/25
1/8
\(\frac{1}{4}\cdot\frac{12}{13}+\frac{1}{4}\cdot\frac{1}{13}-12\%=\frac{1}{4}\cdot\frac{12}{13}+\frac{1}{4}\cdot\frac{1}{13}-\frac{3}{25}=\frac{1}{4}\cdot\left(\frac{12}{13}+\frac{1}{13}\right)-\frac{3}{25}\)
\(=\frac{1}{4}\cdot1-\frac{3}{25}=\frac{1}{4}-\frac{3}{25}=\frac{13}{100}\)
Nhớ bài đây sửa đi sửa lại cũng vì do cái số " % " :(((
a) \(\left|\frac{2}{5}:x\right|=\frac{1}{4}\)
Trường hợp 1 : \(\frac{2}{5}\) : x = \(\frac{1}{4}\)
=> x = \(\frac{2}{5}:\frac{1}{4}=\frac{2}{5}\cdot4=\frac{8}{5}\)
Trường hợp 2 : \(\frac{2}{5}:x=-\frac{1}{4}\)
=> \(x=\frac{2}{5}:\left(-\frac{1}{4}\right)=\frac{2}{5}\cdot\left(-4\right)=-\frac{8}{5}\)
Vậy \(x=\pm\frac{8}{5}\)
b) \(\frac{x}{24}=-\frac{1}{3}-\frac{1}{8}=-\frac{11}{24}\)
=> x = -11
c) \(\frac{3}{x+3}=\frac{-7}{21}\)
=> \(\frac{3}{x+3}=\frac{-1}{3}\)
=> -1(x + 3) = 9
=> -x - 3 = 9
=> -x = 12
=> x = -12
\(\frac{1}{4}.\frac{12}{13}+\frac{1}{4}.\frac{1}{13}-12\%\)
=\(\left(\frac{1}{4}+\frac{1}{4}\right).\left(\frac{12}{13}+\frac{1}{13}\right)-\frac{3}{25}\)
=\(\frac{1}{2}.1-\frac{3}{25}\)
=\(\frac{1}{2}-\frac{3}{25}\)
=\(\frac{25}{50}-\frac{6}{50}\)
=\(\frac{19}{50}\)
Tìm x
a)\(\left|\frac{2}{5}:x\right|=\frac{1}{4}\)
=>\(\hept{\begin{cases}\frac{2}{5}:x=\frac{1}{4}\\\frac{2}{5}:x=\frac{-1}{4}\end{cases}}\)
=>\(\hept{\begin{cases}x=\frac{2}{5}:\frac{1}{4}\\x=\frac{2}{5}:\frac{-1}{4}\end{cases}}\)
=>\(\hept{\begin{cases}x=\frac{8}{5}\\x=\frac{-8}{5}\end{cases}}\)
+)Vậy x \(\varepsilon\left[\frac{8}{5};\frac{-8}{5}\right]\)