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có [x-y]2=1
suy ra [x-y]mũ 2= 1 mũ 2
suy ra x-1=1
x=1+1
x=2
a: \(\Leftrightarrow\left(5x+\dfrac{3}{2}\right):\dfrac{8}{15}=\dfrac{25}{12}-\dfrac{5}{6}=\dfrac{25}{12}-\dfrac{10}{12}=\dfrac{15}{12}=\dfrac{5}{4}\)
\(\Leftrightarrow5x+\dfrac{3}{2}=\dfrac{5}{4}\cdot\dfrac{8}{15}=\dfrac{40}{60}=\dfrac{2}{3}\)
\(\Leftrightarrow5x=\dfrac{2}{3}-\dfrac{3}{2}=\dfrac{4-9}{6}=\dfrac{-5}{6}\)
hay x=-1/6
b: \(\Leftrightarrow\dfrac{1}{4}\left(2-\dfrac{1}{2}x\right)=\dfrac{5}{2}-\dfrac{1}{4}=\dfrac{10}{4}-\dfrac{1}{4}=\dfrac{9}{4}\)
=>2-1/2x=9
=>1/2x=-7
hay x=-14
c: \(\Leftrightarrow\left(x-7\right)^2=144\)
=>x-7=12 hoặc x-7=-12
=>x=19 hoặc x=-5
d: \(\Leftrightarrow4x+2=3x-15\)
hay x=-17
e: =>1/6x=-4
hay x=-24
1) -12.(x-5) + 7.(3-x)=5
-12x+ 60+21-7x =5
-12x-7x = 5-60-21
-19x=-76
x=-76:(-19)
x=4
2) (x-2).(x+4) =0
\(\Rightarrow\)x-2=0 hoặc x+4=0
x-2=0 x+4=0
x=0+2 x=0-4
x=2 x=-4
Vậy x=2 hoặc x=-4
3) (x-2).(x+15) =0
\(\Rightarrow\)x-2=0 hoặc x+15=0
x-2=0 x+15=0
x=0+2 x=0-15
x=2 x=-15
1)\(-12.\left(x-5\right)+7.\cdot\left(3-x\right)=5\)
\(-12x+60+21-7x=5\)
\(-19x+81=5\)
\(-19x=5-81\)
-\(-19x=-76\)
\(x=-76:-19\)
\(x=4\)
2) Ta có 2 trường hợp
TH1: x-2=0 =>x=2
TH2: x+4=0 => x=-4
Vậy \(x\in\left(-4;2\right)\)
3) Ta có
TH1: x-2=0=>x=2
TH2: x+15=0=>x=-15
Vậy \(x\in\left(-15;2\right)\)
a/ 2x . 7 = 224
2x = 224 : 7
2x = 32
2x = 25
x = 5.
b/ 32x + 1 . 11 = 2673
32x + 1 = 2673 : 11
32x + 1 = 243
32x + 1 = 35
32x = 35 - 1
32x = 34
2x = 4
x = 4 : 2
x = 2.
c/ (3x + 5)2 = 289
(3x + 5)2 = 172
3x + 5 = 17
3x = 17 - 5
3x = 12
x = 12 : 3
x = 4.
d/ x . (x2)3 = x5
x1 . x5 = x5
x6 = x5
=> x = 0 hoặc x = 1
a) 2x x 7=224
2x=224:7
2x=32
2x=25
=> x=5
Vậy x=5
b) 32x+1 x 11=2673
32x+1=2673:11
32x+1=243
32x+1=35
=> 2x+1=5
x=(5-1):2
x=2
Vậy x=2
c) (3*x+5)2=289
(3*x+5)2=172
=> 3*x+5=17
x=(17-5):3
x=4
Vậy x=4
d) x.(x2)3=x5
x.x6=x5
x=x5:x6
x=x-1
Có trường hợp x = 2x + 5 nha, mình cứng minh nè
2x + 5 = x
<=> 2x - x = - 5
=> x = - 5
Thử lại 2.( - 5 ) + 5 = - 5 ( đúng )
Có x chia hết cho x/x.2
<=> x:x/x.2 <=> x.x.2/x = 2x là số nguyên
a: =>4y+15/16=1
=>4y=1/16
=>y=1/64
b: =>10y+1/2+1/4+...+1/1024=1
=>10y+1023/1024=1
=>10y=1/1024
=>y=1/10240
1) 6x+2=216=63
=>x+2=3
=>x=1
2)72-(15+x)=5.22
49-15-x=5.4
34-x=20
x=14
3)[(6x-72):2-84].28=5628
(3x-36-84).28=5628
3x-36-84=201
3x-120=201
3x=321
x=107
4)3x-2.4=324
3x-2=81=34
=>x-2=4
x=6
\(6^{x+2}=216\Leftrightarrow6^x=216:6^2=6;x=1\)\(7^2-\left(15+x\right)=5.2^2\Leftrightarrow49-\left(15+x\right)=20\)
\(15+x=49-20=29;x=14\)
\(a,\dfrac{7}{12}-\left(x+\dfrac{7}{10}\right):\dfrac{6}{5}=\dfrac{5}{4}\)
\(\Leftrightarrow\dfrac{7}{12}-x-\dfrac{7}{10}:\dfrac{6}{5}=\dfrac{5}{4}\)
\(\Leftrightarrow\dfrac{7}{12}-x-\dfrac{7}{12}=\dfrac{5}{4}\)
\(\Leftrightarrow\dfrac{7}{12}-x=\dfrac{5}{4}+\dfrac{7}{12}\)
\(\Leftrightarrow\dfrac{7}{12}-x=\dfrac{11}{6}\)
\(\Leftrightarrow x=\dfrac{7}{12}-\dfrac{11}{6}\)
\(\Leftrightarrow\dfrac{-5}{4}\)
\(\dfrac{x-5}{3}=\dfrac{x+7}{2}\\ =>2\left(x-5\right)=3\left(x+7\right)\\ =>2x-10=3x+21\\ =>3x-2x=-10-21\\ =>x=-31\)
Vậy: ...