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x(3-x)=0
Th1: x=0
Th2: 3-x=0 => x=3
Vậy x=0 và x=3
(x+2)(4x-8)=0
Th1: x+2= 0 => x=-2
Th2: 4x-8 =0 => 4x =8
x= 2
Vậy x= +- 2 (cộng trừ 2 nhé)
(x+1)+(x+2)+(x+3)+....+(x+199)=5750
199x +(1+2+3+...199) =5750
199x+ {(199+1)* [(199-1)+1] : 2} =5750
199x + 19900= 5750
199x = -14150
x= -14150/199
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a)= ( 81 , 6 x 27 , 3 – 17 , 3 x 81 , 6 ) x 0
=0 ( vì 0 nhân với số nào cũng bằng 0)
b)= ( 13 , 75 – 0 , 48 x 5 ) x ( 42 , 75 : 3 + 2 , 9 ) x ( 9-9)
= ( 13 , 75 – 0 , 48 x 5 ) x ( 42 , 75 : 3 + 2 , 9 ) x 0
= 0 ( vì 0 nhân với số nào cũng bằng 0)
c)=( 792 , 81 x 0 , 25 + 792 , 81 x 0 , 75 ) x 0
=0 ( vì 0 nhân với số nào cũng bằng 0 )
a ) ( 81 , 6 x 27 , 3 – 17 , 3 x 81 , 6 ) x ( 32 x 11 - 3200 x 0 , 1 - 32 )
= ( 81 , 6 x 27 , 3 – 17 , 3 x 81 , 6 ) x ( 352 - 320 - 32 )
= ( 81 , 6 x 27 , 3 – 17 , 3 x 81 , 6 ) x 0
= 0.
b ) ( 13 , 75 – 0 , 48 x 5 ) x ( 42 , 75 : 3 + 2 , 9 ) x ( 1 , 8 x 5 – 0 , 9 x 10 )
= ( 13 , 75 – 0 , 48 x 5 ) x ( 42 , 75 : 3 + 2 , 9 ) x ( 9 - 9 )
= ( 13 , 75 – 0 , 48 x 5 ) x ( 42 , 75 : 3 + 2 , 9 ) x 0
= 0
c ) ( 792 , 81 x 0 , 25 + 792 , 81 x 0 , 75 ) x ( 11 x 9 – 900 x 0 , 1 – 9 )
= ( 792 , 81 x 0 , 25 + 792 , 81 x 0 , 75 ) x ( 99 - 90 - 9 )
= ( 792 , 81 x 0 , 25 + 792 , 81 x 0 , 75 ) x 0
= 0.
Hok tốt !
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100 x 1 x 2 x3 x 4 x 5 x 6 x 7 x 8 x 9 x 0
= ( 100 x 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9 ) x 0
= 0
P/s : ^^ Học tốt!
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\(25\cdot\left\{8\cdot\left[12-4+8\left(16\div80\right)\right]\right\}\)
\(=25\cdot\left\{8\cdot\left[12-4+8\cdot0,2\right]\right\}\)
\(=25\cdot\left\{8\cdot8+1,6\right\}\)
\(=25\cdot\left(64+1,6\right)\)
\(=25\cdot65,6=1640\)
b)\(2016\cdot0+1\left(207+\frac{0}{4579}\right)=0+1\cdot207=207\)
c)\(15\cdot\left\{2100\div\left[251-\left(16+84\cdot2\right)\right]\right\}\)
\(=15\cdot\left\{2100\div\left[251-\left(16+168\right)\right]\right\}\)
\(=15\cdot\left\{2100\div\left[251-184\right]\right\}\)
\(=15\cdot\left(2100\div67\right)\)
\(=15\cdot\frac{2100}{67}=\frac{31500}{67}\)
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0, 9 x 95 + 1, 8 x 2 + 0, 9
= 0,9 x 95 + 0,9 x 2 x 2 + 0,9
= 0,9 x 95 + 0,9 x 4 + 0,9
= 0,94 x ( 95 + 4 + 1 )
= 0,94 x 100
= 94
Nhớ k cho mk nha ^_^
=0.9 x 95 +0.9 x 2 x 2 + 0.9 x 1
=0.9 x (95+4+1)
=0.9 x 100
=90
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Ta có :
3/8 - 3/8 x ( x - 1 ) = 0
3/8 x ( x - 1 ) = 3/8
x - 1 = 3/8 - 3/8
x - 1 = 0
x = 0 + 1
x = 1
Vậy x = 1 thì biểu thức trên có giá trị bằng 0
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1) 5(x - 2) + 27 = 4x - 8
=> 5x - 10 + 27 = 4x - 8
=> 5x + 17 = 4x - 8
=> 5x - 4x = -8 - 17
=> x = -25
2) 3(x + 1) + 2(x + 2) = -13
=> 3x + 3 + 2x + 4 = -13
=> 5x + 7 = -13
=> 5x = -13 - 7
=> 5x = -20
=> x = -20 : 5
=> x = -4
3) (2x + 4)(5 - x) = 0
=> \(\orbr{\begin{cases}2x+4=0\\5-x=0\end{cases}}\)
=> \(\orbr{\begin{cases}2x=-4\\x=5\end{cases}}\)
=> \(\orbr{\begin{cases}x=-2\\x=5\end{cases}}\)
Vậy ...
4) x2 - 3x = 0
=> x(x - 3) = 0
=> \(\orbr{\begin{cases}x=0\\x-3=0\end{cases}}\)
=> \(\orbr{\begin{cases}x=0\\x=3\end{cases}}\)
Vậy ...
5) x2 - 3x + 2 = 0
=> x(x - 3) = -2
=> x(x - 3) = 1 . (1 - 3)
=> x = 1
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a) x - 26 : 13 = 2017
x - 2 = 2017
x = 2017 + 2
x = 2019
b) \(\frac{2}{3}+\frac{1}{3}.\left(x+28\right)=18\)
\(\frac{1}{3}.\left(x+28\right)=18-\frac{2}{3}\)
\(\frac{1}{3}.\left(x+28\right)=\frac{54}{3}-\frac{2}{3}\)
\(\frac{1}{3}.\left(x+28\right)=\frac{52}{3}\)
\(x+28=\frac{52}{3}:\frac{1}{3}\)
\(x+28=52\)
\(x=52-28\)
\(x=24\)
c) \(\frac{7}{8}.\left(x-27\right)=\frac{9}{8}-0,125\)
\(\frac{7}{8}.\left(x-27\right)=1\)
\(x-27=1:\frac{7}{8}\)
\(x-27=\frac{8}{7}\)
\(x=\frac{8}{7}+27\)
\(x=\frac{8}{7}+\frac{189}{7}\)
\(x=\frac{197}{7}\)
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4 + x = 7 - 2x
4 + x + 2x = 7
4 + 3x = 7
3x = 7 - 4
3x = 3
x = 3 : 3
x =1
5 + x = 8,3 + 4,7 - x
5 + x + x = 8,3 + 4,7
5 + 2x = 13
2x = 13 - 5
2x = 8
x = 8 : 2
x= 4
x.(x-1) = 0
(x-1) = 0 :x = 0
x = 0 + 1 = 1
vậy x = 1