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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
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a) 3(x - 2) + 150 = 204
=> 3(x - 2) = 204 - 150
=>3(x - 2) = 54
=> x - 2 = 54 : 3
=> x - 2 = 18
=> x = 18 + 2
=> x = 20
b) (x - 13) : 5 = 12
=> x - 13 = 12 x 5
=> x - 13 = 60
=> x = 60 + 13
=> x = 73
3 ( x - 2 ) + 150 = 204
\(3\left(x-3\right)=54\)
\(\left(x-3\right)=18\)
\(x=21\)
( x - 13 ) : 5 = 12
\(x-13=60\)
\(x=73\)
24 + 3 ( 5 - x ) =27
\(3\left(5-x\right)=3\)
\(5-x=1\)
\(x=4\)
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a) \(y-6:2-\left(48-24.2:6-3\right)=0.\)
\(\Rightarrow y-3-\left(48-8-3\right)=0\)
\(\Rightarrow y-3-37=0\)
\(\Rightarrow y=0+37+3=40\)
Vậy y = 40
b) \(\left(7.13+8.13\right):\left(9\frac{2}{3}-y\right)=39\)
\(\Rightarrow195:\left(\frac{29}{3}-y\right)=39\)
\(\Rightarrow\frac{29}{3}-y=195:39=5\)
\(\Rightarrow y=\frac{29}{3}-5=\frac{14}{3}\)
Vậy y=\(\frac{14}{3}\)
a) y - 6 : 2 - ( 48 - 24 x 2 : 6 - 3 ) = 0
y - 6 : 2 - ( 48 - 48 : 6 - 3 ) = 0
y - 6 : 2 - ( 48 - 8 - 3 ) = 0
y - 6 : 2 - 37 = 0
y - 3 = 0 + 37
y - 3 = 37
y = 37 + 3
y = 40
b) ( 7 x 13 + 8 x 13 ) : ( \(9\frac{2}{3}\) - y ) = 39
( 15 x 13 ) : ( \(9\frac{2}{3}\) - y ) = 39
195 : ( \(9\frac{2}{3}\) - y ) = 39
\(9\frac{2}{3}\) - y = 195 : 39
\(9\frac{2}{3}-y=5\)
\(y=9\frac{2}{3}-5\)
\(y=\frac{14}{3}\)
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a: =>13^x*3=7-4*13=7-52=-45
=>13^x=-15(loại)
b: Sửa đề: \(4^{x+1}\cdot11-4^{x+2}\cdot2=24:2^2\)
=>\(4^x\cdot4\cdot11-4^x\cdot16\cdot2=6\)
=>4^x=6/(4*11-16*2)=6/(44-32)=6/12=1/2
=>\(x\in\varnothing\)
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1) = 35 . 18 - 35 . 18 = 0
2) = 45 - 5 . 12 + 5 . 9 = 45 - 60 + 45 = 30
3) = 24 . 16 - 24 . 5 - 16 . 24 - 16 . 5
= (24 . 16 - 16 . 24) - 5 (24 - 16)
= 0 - 5 . 8 = 0 - 40 = -40
4) = 29 . 19 - 29 . 13 - 19 . 29 - 19 . 13
= (29 . 19 - 29 . 19) - 13 (29 - 19)
= 0 - 13 . 10 = 0 - 130 = -130
5) = 31 . (-18) + 31 . (-81) - 31 . 1
= 31 [(-18) + (-81) - 1]
= 31 . (-100) = -3100
6) = (-12) . 47 + (-12) . 52 + (-12). 1
= (-12) . (47 + 52 + 1)
= (-12) . 100 = -1200
7) = 13 . 45 - 3 . 45
= 45 (13 - 3)
= 45 . 10 = 450
8) = (-48) + 48 . (-78) + 48 . (-21)
= (-48) . 1 + 48 . (-78) + 48 . (-21)
= 48 . (-1) + 48 . (-78) + 48 . (-21)
= 48 . [(-1) + (-78) + (-21)]
= 48 . (-100) = -4800
1) 35x18-5x7x18
= 35x18-35x18
= 35x(18-18)
= 35x0=0
3) 24.(16-5)-16.(24-5)
= 24.16-24.5-16.24-16.5
=[24.16-16.24]-[24.5-16.5]
= [ 24. (16-16)]- [(24-16).5]
= [24.0]-[8.5]
= 0-40=-40
4) 29.(19-13)-19.(29-13)
=29.19-29.13-19.29-19.13
=[ 29.19-19.29]-[ 29.13-19.13]
= [ 29.(19-19)]-[(29-19).13]
=[29.0]-[10.13]
= 0-130= -130
5) 31.(-18)+31.(-81)-31
= 31.(-18)+31.(-81)-31.1
= 31.[(-18)+(-81)-1]
=31.(-100)
= -3100
6);7);8 tương tự 4);5);6)
\(3\times\frac{24}{13}+2\times\frac{3}{13}=\frac{72}{13}+\frac{6}{13}=\frac{78}{13}=6\)
3x24/13+2x3/13
=3x8x3/13+2x3/13
=24x3/13+2x3/13
=3/13x(24+2)
=3/13x26
=6