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a) \(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)
\(\dfrac{2}{3}x=\dfrac{1}{10}+\dfrac{1}{2}=\dfrac{3}{5}\)
\(x=\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{9}{10}\)
b) \(\dfrac{39}{7}:x=13\)
\(x=\dfrac{\dfrac{39}{7}}{13}=\dfrac{3}{7}\)
c) \(\left(\dfrac{14}{5}x-50\right):\dfrac{2}{3}=51\)
\(\dfrac{14}{5}x-50=51\cdot\dfrac{2}{3}=34\)
\(\dfrac{14}{5}x=34+50=84\)
\(x=\dfrac{84}{\dfrac{14}{5}}=30\)
d) \(\left(x+\dfrac{1}{2}\right)\left(\dfrac{2}{3}-2x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{2}=0\\\dfrac{2}{3}-2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)
e) \(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{12}\)
\(\dfrac{1}{6}x=\dfrac{5}{12}\)
\(x=\dfrac{5}{12}:\dfrac{1}{6}=\dfrac{5}{2}\)
g) \(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\dfrac{11}{5}-\dfrac{3}{7}=-2\)
\(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\cdot\dfrac{11}{5}=-2+\dfrac{3}{7}=-\dfrac{11}{7}\)
\(x\cdot\dfrac{44}{7}+\dfrac{3}{7}=-\dfrac{11}{7}:\dfrac{11}{5}=-\dfrac{5}{7}\)
\(\dfrac{44}{7}x=-\dfrac{5}{7}-\dfrac{3}{7}=-\dfrac{8}{7}\)
\(x=-\dfrac{8}{7}:\dfrac{44}{7}=-\dfrac{2}{11}\)
h) \(\dfrac{13}{4}x+\left(-\dfrac{7}{6}\right)x-\dfrac{5}{3}=\dfrac{5}{12}\)
\(\dfrac{25}{12}x-\dfrac{5}{3}=\dfrac{5}{12}\)
\(\dfrac{25}{12}x=\dfrac{5}{12}+\dfrac{5}{3}=\dfrac{25}{12}\)
\(x=1\)
Mỏi tay woa bn làm nốt nha!!
a, 410. 230=220.230=250
b,925.274.813= 350.312.312=374
Tương tự các câu khác....
a, 410.230 = (22)10.230 = 220.230 = 250
b, 925.274.813 = (32)25.(33)4.(34)3 = 350.312.312 = 374
c, 2550.1255 = (52)50.(53)5 = 5100.515 = 5115
d, 643.48.164 = (26)3.(22)8.(24)4 = 218.216.216 = 250
e, 38 : 36 = 32
210 : 83 = 210 : (23)3 = 210 : 29 = 2
127 : 67 = (12 : 6)7 = 27
@Dương Tuyết Mai
A. x = 2
B. \(\dfrac{3}{8}=\dfrac{6}{x}\)\(\Leftrightarrow x=\dfrac{6.8}{3}=16\)
C. x = 3
D. \(x=\dfrac{4.6}{8}=3\)
E. \(x=\dfrac{7}{3}\)
G.\(\dfrac{14}{13}=\dfrac{28}{10-x}\)
<=>\(14\left(10-x\right)=364\)
<=> 10 - x = 26
<=> x = -16
H. \(3\left(x+2\right)=4\left(x-5\right)\)
<=> 3x + 6 = 4x - 20
<=> -x = -26
<=> x = 26
K. \(\dfrac{x}{2}=\dfrac{8}{x}\)
<=> \(x^2=16\)
<=> \(\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)
M. \(\left(x-2\right)^2=100\)
<=> \(\left[{}\begin{matrix}x-2=10\\x-2=-10\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=12\\x=-8\end{matrix}\right.\)
a=2
b=16
c=3
d=3
mik chỉ biết thế này thôi(ko chắc đúng=3)
XÝ a mik ko hiểu
b) x-52=-4
x-25=-4
x=-4+25
x=21
c) x+33=23
x-27=8
x=8+27
x=35
d) \(|x-7|+9=-3\)
\(|x-7|=\left(-3\right)+9\)
\(|x-7|=6\)
\(|x|=6+7\)
\(\Rightarrow x=13\)hoặc \(x=-13\)
Thoi chán òi hổng lèm nửa âu~~
Trả lời :
Làm tiếp nha :)
e ) | 5 - x | - 7 = -3
\(=>\) \(\left|5-x\right|\) \(=\) \(-3+7\) \(=\) \(4\)
\(=>\) \(\orbr{\begin{cases}5-x=4\\5-x=-4\end{cases}}\)\(=>\) \(\orbr{\begin{cases}x=5-4\\x=5-\left(-4\right)\end{cases}}\)\(=>\) \(\orbr{\begin{cases}x=1\\x=9\end{cases}}\)
g ) 4x : 2 = 32
<=> 4x = 32 x 2
<=> 4x = 64
<=> 4x = 43
=> x = 3
h ) mk chưa hiểu lắm ^^
k ) x10 = x8 => x = 0 hoặc 1 ( mk nghĩ vậy )
_Vì 010 = 08 ; 110 = 18
_Học tốt nhea
1 .
a) 2155-(174+2155)+(-68+174)
=2155-174-2155-68+174
=(2155-2155)+(-174+174)-68
=-68
b) 35(14-23)-23(14-35)
=35.(-9) - 23.(-21)
=-315+483
=168
c) -1911-(1234-1911)
= -1911-1234+1911
=(-1911+1911)-1234
=-1234
d) 32.(-39)+16.(-22)
=16[2.(-39)-22]
=16(-78-22)
=16.(-100)
=-1600
2. Tìm x
a) 3x+17=2
=>3x=-15
=>x=-5
b) -5x -(-3)=13
=>-5x+3=13
=>-5x=10
=>x=-2
c) 45-(x-9)=-35
=>x-9=80
=>x=89
d) 15-(x-7)= -21
=>x-7=36
=>x=43
e) (7-x).(x+19)=0
=>7-x=0 hoặc x+19=0
+)TH1: 7-x=0=>x=7
+)TH2: x+19=0=>x=-19
P/s: Tự KL nhé