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48∈B(2x+1)
⇒48⋮2x+1
⇒2x+1∈Ư(48)
Ư(48)={1;2;3;4;6;8;12;16;24;48}
⇒x∈{0;1}
\(2x+1\inƯ\left(48\right)\)
\(\Leftrightarrow2x+1\in\left\{1;3\right\}\)
hay \(x\in\left\{0;1\right\}\)
12x - 10x + 54 = 86
\(\Rightarrow\)12x - 10x = 86 - 54
\(\Rightarrow\)2x = 32
\(\Rightarrow\)x = 32 : 2
\(\Rightarrow\) x= 16
12x-10x+54=86
=(12-10)x+54=86
(12-10)x =32
2x =32
x =32chia2
x =16
a) x/-2=-4/y=2/4
*x/-2=2/4=>4x=(-2)x2=>x=-1
*-4/y=2/4=>(-4)x4=2y=>y=-8
b)2/x=y/-3
=>xy=-6(câu này đề hơi lạ)
c) x+1/2=8/x+1
=>16=(x+1)(x+1)=>x^2+2x+1=16=>(x+1)^2=16=>(x+1)^2=4^2=>x+1=4=>x=3
a/ 128 . 3 . (x + 4) = 23
=> 384. (x + 4) = 23
=> x + 4 = 23/384
=> x = -1513/384
b/ 100 - 7 .(x + 5) = 58
=> 7. (x + 5) = 42
=> x + 5 = 6
=> x = 1
\(b,\left(x+1\right)\times3=8\)
\(\Leftrightarrow x+1=\frac{8}{3}\)
\(\Leftrightarrow x=\frac{8}{3}-1\)
\(\Leftrightarrow x=\frac{5}{3}\)
\(c,\left(21-3\right)^3=-27\)
\(\Leftrightarrow\left(21-3\right)^3=\left(-3\right)^3\)
\(\Leftrightarrow21-3=-3\)\(???\)ĐỀ SAI RỒI BẠN
\(a,\left[12\times\left(-4^3\right)\right]\times8^3=4\times\frac{8}{7}\)
\(\left[12\times\left(-64\right)\right]\times512=\frac{32}{7}\)
\(-768\times512=\frac{32}{7}\)\(???\)ĐỀ SAI RỒI BẠN
a, 7x + 10x = 5x
17x = 5x
17x - 5x = 0
12x = 0
x =0
2;
a, 4x + 7x = 22
11x = 22
x = 2
b, 12x - 8x = 25
4x = 25
x = \(\dfrac{25}{4}\)
c, \(\dfrac{1}{2}\)x - \(\dfrac{1}{3}\)x = \(\dfrac{4}{5}\)
(\(\dfrac{1}{2}-\dfrac{1}{3}\))x = \(\dfrac{4}{5}\)
\(\dfrac{1}{6}\)x = \(\dfrac{4}{5}\)
x = \(\dfrac{4}{5}\) : \(\dfrac{1}{6}\)
x = \(\dfrac{24}{5}\)
\(\frac{1}{3.5}+\frac{1}{5.7}+\frac{1}{7.9}+...+\frac{1}{\left(2x+1\right).\left(2x+3\right)}=\frac{15}{93}\)
\(2.\left(\frac{1}{3.5}+\frac{1}{5.7}+\frac{1}{7.9}+...+\frac{1}{\left(2x+1\right).\left(2x+3\right)}\right)=2.\frac{15}{93}\)
\(\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+...+\frac{2}{\left(2x+1\right).\left(2x+3\right)}=\frac{30}{93}\)
\(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+...+\frac{1}{2x+1}-\frac{1}{2x+3}=\frac{10}{31}\)
\(\frac{1}{3}-\frac{1}{2x+3}=\frac{10}{31}\)
\(\frac{1}{2x+3}=\frac{1}{3}-\frac{10}{31}\)
\(\frac{1}{2x+3}=\frac{1}{93}\)
=> 2x + 3 = 93
=> 2x = 93 - 3
=> 2x = 90
=> x = 90 : 2
=> x = 45
Vậy x = 45
Bài 1:
a: \(\Leftrightarrow\dfrac{6}{7}\left(\dfrac{7}{12}x-\dfrac{14}{3}\right)=\dfrac{5}{9}-\dfrac{9}{8}=\dfrac{-41}{72}\)
\(\Leftrightarrow x\cdot\dfrac{7}{12}-\dfrac{14}{3}=-\dfrac{287}{432}\)
\(\Leftrightarrow x\cdot\dfrac{7}{12}=\dfrac{1729}{432}\)
hay \(x=\dfrac{247}{36}\)
b: \(\Leftrightarrow\dfrac{1}{5}:x=\dfrac{1}{5}+\dfrac{3}{14}-\dfrac{8}{7}=\dfrac{-51}{70}\)
hay \(x=-\dfrac{14}{51}\)
c: đề sai rồi bạn
a) 96 - 3 (x - 1) = 42
3 (x - 1) = 96 - 42
3 (x -1) = 54
x - 1 = 54 : 3
x - 1 = 18
x = 18 + 1
x = 19
b) 12x - 33 = 32 . 33
12x - 33 = 35
12x - 33 = 243
12x = 243 + 33
12x = 276
x = 276 : 12
x = 23
Bạn nhớ kiểm tra lại nha dinh nguyen
96 - 3( x+ 1 ) = 42
3( x + 1 ) = 96 - 42
3( x + 1 ) = 54
x + 1 = 54 : 3
x + 1 = 18
x = 18 - 1
x = 17
12x - 33 = 3 ^ 2 . 3 ^ 3
12x - 33 = 9 . 27
12x - 33 = 243
12x = 243 + 33
12x = 276
x = 276 : 12
x = 23
a) 12x - 10x + x = 24
x(12-10+1) =24
x3 =24
x =24:3=8
b)22x-1 - 7 = 1
22x:2-7 =1
4x:2 =1+7
4x =8.2
4x =16
ma 4.4=16
=>x=2
12x - 10x + x = 24
(12-10+1) . x = 24
3 . x = 24
x = 24 : 3
x = 8
Vậy x = 8
----------------------------------
22x-1 - 7 = 1
22x-1 = 1+ 7
22x-1 = 8
Ta thấy : 8 = 2.2.2 ( 3 lần số 2 )
suy ra : 2x-1 =3
2x = 3+1
2x = 4
x = 4 : 2
x = 2
Vậy x = 2