Tìm x biết: (1-52/53) + (105/106 - 1) + ( 158/159 - 1) = |x|/318
Tìm x biết:
a, (1- 52/53)+(105/106-1)+(158/159-1)=|x|/318
=> \(\frac{1}{53}\)+ \(\frac{-1}{106}\)+\(\frac{-1}{159}\)= \(\frac{\left|x\right|}{318}\)
=> \(\frac{1}{318}\)= \(\frac{\left|x\right|}{318}\)
=> x thuộc {1; -1}
\(\left(1-\frac{52}{53}\right)+\left(\frac{105}{106}-1\right)+\left(\frac{158}{159}-1\right)=\frac{\left|x\right|}{318}\)
\(\Rightarrow\frac{1}{53}+\frac{-1}{106}+\frac{-1}{159}=\frac{\left|x\right|}{318}\)
\(\Rightarrow\frac{1}{318}=\frac{\left|x\right|}{318}\)
\(\Rightarrow\left|x\right|=1\)
\(\Rightarrow x=\pm1\)
Vậy..............................
Tìm x biết: \(\left(1-\dfrac{52}{53}\right)+\left(\dfrac{105}{106}-1\right)+\left(\dfrac{158}{159}-1\right)=\dfrac{\left|x\right|}{318}\)
\(\left(1-\frac{52}{53}\right)+\left(\frac{105}{106}-1\right)+\left(\frac{158}{159}-1\right)=\frac{\left|x\right|}{318}\)
⇔\(\frac{1}{53}+\frac{-1}{106}+\frac{-1}{159}=\frac{\left|x\right|}{318}\)
⇔\(\frac{1}{138}=\frac{\left|x\right|}{318}\)
⇒\(\left|x\right|=1\)
⇔\(\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)
Vậy x∈\(\left\{-1;1\right\}\)
a) (1-\(\frac{52}{53}\)) +(\(\frac{105}{106}\)-1) + (\(\frac{158}{159}\)-1) = \(\frac{\left|x\right|}{318}\)
tính nhanh
763 x 28 + 1364 x 21 + 14 x 474 + 42 x 318 =............................................................................................................................................................................................................................................................................................................................................................................................................
312312/131131 x 524524/104104 =............................................................................................................................................................................................................................................................................................................................................................................................................
( 1 + 1/105 ) x ( 1 + 1/106 ) x ( 1/107 ) =....................................................................................................................................................................................................................................................................................................................................................................................................
143x14x30/35x78x44 =....................................................................................................................................................................................................................................................................................................................................................................................................
1919/2323 x 464646/747474 x 37/19 = ......................................................................................................................................................................................................................................................................................................................................................................................................
tìm x
71 + 65 . 4 = x + 140 / x + 260
tính nhanh
38 + 41 + 117 + 159 + 62
341 . 67 + 341 .16 + 659 . 83
42 . 53 + 47 . 156 - 47 . 114
ko tính giá trị so sánh 2 bt
A = 199 . 201 và B = 200 . 200
C = 35 . 53 - 18 và D = 35 + 53 . 18
tìm x
( x + 74 ) - 318 = 200
3636 : ( 12x - 91 ) = 36
( x : 23 + 45 ) . 67 = 8911
tính nhanh
( 44 . 52 . 60 ) : ( 11 . 13 .15 )
Lạy má cả 4 chân tay bài dài thì ai làm nổi
Mong bạn thông cảm
~~~ Chúc bạn học giỏi ~~~
Bài 1: Tìm x là số tự nhiên, biết:
1. Cho A = 21 + 22 + 23 + ....... + 22022
2. Cho B = 5 + 52 + 53 +...........+ 52022
a) Tính A,B
b) Tìm x để A + 2 = 2x
Tìm x để biết 4B + 5 = 5x
Nhanh giúp mình với ạ!
a) Ta có A = 21 + 22 + 23 + ... + 22022
2A = 22 + 23 + 24 + ... + 22023
2A - A = ( 22 + 23 + 24 + ... + 22023 ) - ( 21 + 22 + 23 + ... + 22022 )
A = 22023 - 2
Lại có B = 5 + 52 + 53 + ... + 52022
5B = 52 + 53 + 54 + ... + 52023
5B - B = ( 52 + 53 + 54 + ... + 52023 ) - ( 5 + 52 + 53 + ... + 52022 )
4B = 52023 - 5
B = \(\dfrac{5^{2023}-5}{4}\)
b) Ta có : A + 2 = 2x
⇒ 22023 - 2 + 2 = 2x
⇒ 22023 = 2x
Vậy x = 2023
Lại có : 4B + 5 = 5x
⇒ 4 . \(\dfrac{5^{2023}-5}{4}\) + 5 = 5x
⇒ 52023 - 5 + 5 = 5x
⇒ 52023 = 5x
Vậy x = 2023
Tính nhanh:
( 1 + 1/105 ) x ( 1 + 1/106 ) x ( 1+ 1/107 ) x ( 1+ 1/108 ) x ( 1+ 1/109 )
\(=\frac{106}{105}.\frac{107}{106}.\frac{108}{107}.\frac{109}{108}.\frac{110}{109}\)
\(=\frac{106.107.108.109.110}{105.106.107.108.109}\)
\(=\frac{110}{105}=\frac{22}{21}.\)
Tính nhanh:
( 1 + 1/105 ) x ( 1 + 1/106 ) x ( 1+ 1/107 ) x ( 1+ 1/108 ) x ( 1+ 1/109 )
\(=\frac{106}{105}\times\frac{107}{106}\times\frac{108}{107}\times\frac{109}{108}\times\frac{110}{109}\)
\(=\frac{110}{105}=\frac{22}{21}\)
Tính nhanh:
( 1 + 1/105 ) x ( 1 + 1/106 ) x ( 1+ 1/107 ) x ( 1+ 1/108 ) x ( 1+ 1/109 )