Đề bài kiểu gì vậy bạn,mình không hiểu

mk cũng ko hiểu đề bài lun

D

D

\(\dfrac{\dfrac{7}{13}+\dfrac{7}{14}-\dfrac{7}{15}}{\dfrac{8}{13}+\dfrac{8}{14}-\dfrac{8}{15}}-\dfrac{\dfrac{5}{11}-\dfrac{5}{13}+\dfrac{5}{15}}{\dfrac{8}{11}-\dfrac{8}{13}+\dfrac{8}{15}}\)

\(=\dfrac{7\left(\dfrac{1}{13}+\dfrac{1}{14}-\dfrac{1}{15}\right)}{8\left(\dfrac{1}{13}+\dfrac{1}{14}-\dfrac{1}{15}\right)}-\dfrac{5\left(\dfrac{1}{11}-\dfrac{1}{13}+\dfrac{1}{15}\right)}{8\left(\dfrac{1}{11}-\dfrac{1}{13}+\dfrac{1}{15}\right)}\)

\(=\dfrac{7}{8}-\dfrac{5}{8}\)

\(=\dfrac{2}{8}=\dfrac{1}{4}\)

=7/8 - 5/8 =1/4

A

A

khó quá mk giải miết mà không ra

khó vãi

Tính nhẩm nha m.n

Làm 1 câu

10/3...>...1/3

Mấy câu ssu tự quy đồng hay gì gì đấy!

10/3.>..1/3.     10/6.>..3/8.     17/4.>..5/6.    1/3..<.5/9     5/8.<..7/5    3/4..<.15/6      10/9.>..10/11   7/8..<.7/2       15/9.>..3/8  15/7.>..15/8      16/5.>..16/7    25/11..<.1

can you tách ra đc hum

`@` `\text {Ans}`

`\downarrow`

`x^3 = 125`

`=> x^3 = 5^3`

`=> x = 5`

Vậy, `x = 5`

_____

`4^5 \div 4^3`

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

`= 4^2`

______

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

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

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

______

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

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

`=`\(7^2\)

_______

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

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

`= 17^3`

_______

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

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

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

`= 5`

_______

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

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

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

`= 15`

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

\(x^3=125\)

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

\(\Rightarrow x=3\)

___________________

\(4^5:4^3\)

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

\(=4^2=16\)

___________________

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

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

\(=1\)

___________________

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

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

\(=7^2=49\)

___________________

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

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

\(=17^3=4913\)

___________________

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

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

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

\(=5^1=5\)

___________________

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

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

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

\(=15^1=15\)

__________________

* aⁿ . a^m = a^n+m

 aⁿ : a^m = a^n-m

Chúc bạn học tốt

5 × 8 – 20 = 40 – 20 = 20

5 × 4  + 8 = 20 + 8 = 28

4 × 7 – 18 = 28 – 18 = 10.