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30 tháng 11 2023

[15 + (1.27 -8)]: (-17)

= [15 + (27 -8)]: (-17)

= [15 + 19]:(-17)

= 34 :(-17)

= -2

`@` `\text {Ans}`

`\downarrow`

`x^3 = 125`

`=> x^3 = 5^3`

`=> x = 5`

Vậy, `x = 5`

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`4^5 \div 4^3`

`=`\(4^{5-3}\)

`= 4^2`

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\(8^{12}\cdot8^3\div8^{15}\)

`=`\(8^{12+3-15}\)

`=`\(8^0=1\)

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\(7^{15}\div7^{13}\)

`=`\(7^{15-13}\)

`=`\(7^2\)

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\(17^{15}\cdot17^{10}\div17^{22}\)

`=`\(17^{15+10-22}\)

`= 17^3`

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\(5^{10}\cdot25\div5^{11}\)

`=`\(5^{10}\cdot5^2\div5^{11}\)

`=`\(5^{10+2-11}\)

`= 5`

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\(15^{10}\cdot225\div15^{11}\)

`=`\(15^{10}\cdot15^2\div15^{11}\)

`=`\(15^{12}\div15^{11}\)

`= 15`

`@` `\text {Kaizuu lv uuu}`

10 tháng 7 2023

\(x^3=125\)

\(\Rightarrow x^3=5^3\)

\(\Rightarrow x=3\)

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\(4^5:4^3\)

\(=4^{5-3}\)

\(=4^2=16\)

 

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\(8^{12}.8^3:8^{15}\)

\(=8^{15}:8^{15}\)

\(=1\)

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\(7^{15}:7^{13}\)

\(=7^{15-13}\)

\(=7^2=49\)

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\(17^{15}.17^{10}:17^{22}\)

\(=17^{25}:17^{22}\)

\(=17^3=4913\)

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\(5^{10}.25:5^{11}\)

\(=5^{10}.5^2:5^{11}\)

\(=5^{12}:5^{11}\)

\(=5^1=5\)

___________________

\(15^{10}.225:15^{11}\)

\(=15^{10}.15^2:15^{11}\)

\(=15^{12}:15^{11}\)

\(=15^1=15\)

__________________

* a. a= an+m

 an : am = an-m

Chúc bạn học tốt

3 tháng 9 2021

\(\dfrac{3}{17}+\dfrac{-8}{15}+\dfrac{-3}{17}+\dfrac{8}{15}+\dfrac{2018}{2019}=\left(\dfrac{3}{17}-\dfrac{3}{17}\right)+\left(\dfrac{8}{15}-\dfrac{8}{15}\right)+\dfrac{2018}{2019}=\dfrac{2018}{2019}\)

\(\dfrac{3}{17}+\dfrac{-8}{15}+\dfrac{-3}{17}+\dfrac{8}{15}+\dfrac{2018}{2019}\)

\(=0+0+\dfrac{2018}{2019}\)

\(=\dfrac{2018}{2019}\)

`#3107.101107`

\(-16 \div (-8)+5[3-15\div5+2(-3+4)]\)

`= 2 + 5(3 - 3 - 6 + 8)`

`= 2 + 5*(-6 + 8)`

`= 2 + 5*2`

`= 2(5 + 1)`

`= 2*6 = 12`

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`15*(-236)+15*235`

`= 15 * (-236 + 235)`

`= 15 * (-1)`

`= -15`

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`237*(-28)+28*137`

`= 28 * (-237 + 137)`

`= 28 * (-100)`

`= -2800`

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`(-3)*(-17)+3*(120-17)`

`= 3 * 17 + 3 * (120 - 17)`

`= 3 * (17 + 120 - 17)`

`= 3 * 120`

`= 360`

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`(-8)*72+8*(-19)-(-8)`

`= 8 * (-72) + 8 * (-19) + 8`

`= 8 * (-72 - 19 + 1)`

`= 8 * (-90)`

`= -720`

24 tháng 12 2023

a)−16÷(−8)+5[3−15÷5+2(−3+4)]

=2+5(3−3−6+8)

=2+5⋅(−6+8)

=2+5⋅2

=2(5+1)

=2⋅6

=12

b)15⋅(−236)+15⋅235

=15⋅(−236+235)

=15⋅(−1)

=−15

c)237⋅(−28)+28⋅137

=28⋅(−237+137)

=28⋅(−100)

=−2800

d)(−3)⋅(−17)+3⋅(120−17)

=3⋅17+3⋅(120−17)

=3⋅(17+120−17)

=3⋅120

=360

e)(−8)⋅72+8⋅(−19)−(−8)

=8⋅(−72)+8⋅(−19)+8

=8⋅(−72−19+1)

=8⋅(−90)

=−720

19 tháng 6 2015

rõ ràng ta chỉ cần so sánh giữa \(15^{30}+16^{12}+17^{50}-16^8\) và \(17^{30}+16^8+15^{50}-16^{12}\)

Áp dụng tính chất nếu a>b thì a-b>0 ta được:

   \(15^{30}+16^{12}+17^{50}-16^8\)\(\left(17^{30}+16^8+15^{50}-16^{12}\right)\)

\(\left(17^{50}-17^{30}\right)+\left(16^{12}+16^{12}\right)+\left(15^{30}-15^{50}\right)-\left(16^8+16^8\right)\)

\(\left(17^{50}-17^{30}\right)+\left(15^{30}-15^{50}\right)+2\left(16^{12}-16^8\right)\)

Vì 17^50 - 17^30 > l 15^30 - 15^50 l 

nên \(\left(17^{50}-17^{30}\right)+\left(15^{30}-15^{50}\right)>0\)

=>\(15^{30}+16^{12}+17^{50}-16^8\)\(17^{30}+16^8+15^{50}-16^{12}\)

=> Phân số thứ nhất > 1 và p/s thứ hai < 1

Lúc này bạn tự so sánh nha

\(=\dfrac{8}{23}+\dfrac{3}{19}-\dfrac{15}{17}-\dfrac{2}{17}+\dfrac{15}{23}=\dfrac{3}{19}\)

15 tháng 2 2022

\(\left(\dfrac{8}{23}+\dfrac{3}{19}-\dfrac{15}{17}\right)-\left(\dfrac{2}{17}-\dfrac{15}{23}\right)\\ =\dfrac{8}{23}+\dfrac{3}{19}-\dfrac{15}{17}-\dfrac{2}{17}+\dfrac{15}{23}\\ =\left(\dfrac{8}{23}+\dfrac{15}{23}\right)-\left(\dfrac{15}{17}+\dfrac{2}{17}\right)+\dfrac{3}{19}\\ =1-1+\dfrac{3}{19}\\ =\dfrac{3}{19}\)

13 tháng 6 2023

\(\dfrac{12}{17}.\dfrac{9}{13}-\dfrac{7}{15}.\dfrac{6}{13}+\dfrac{5}{17}.\dfrac{9}{13}-\dfrac{8}{15}.\dfrac{6}{13}\)

\(=\dfrac{9}{13}.\left(\dfrac{12}{17}+\dfrac{5}{17}\right)-\dfrac{6}{13}.\left(\dfrac{7}{15}+\dfrac{8}{15}\right)\)

\(=\dfrac{9}{13}.\dfrac{17}{17}-\dfrac{6}{13}.\dfrac{15}{15}\)

\(=\dfrac{9}{13}.1-\dfrac{6}{13}.1\)

\(=\dfrac{9}{13}-\dfrac{6}{13}\)

\(=\dfrac{9-6}{13}\)

\(=\dfrac{3}{13}\)