`(12x-4^3). 8^13=4. 8^14`

`=> 12x-64=4.8`

`=> 12x-64=32`

`=> 12x=96`

`=> x=8`

500-(5x+70)=\(5^2\).4

500-(5x+70)=25.4

500-(5x+70)=100

5x+70=500-100

5x+70=400

5x=400-70

5x=330

x=330:5

x=66

vậy.....

GIÚP MÌNH GIẢI NHANH CÂU NÀY Ạ:)

    (x-5)(x-7)=0

⇔ \(\left\{{}\begin{matrix}x-5=0\\x-7=0\end{matrix}\right.\)

⇔\(\left\{{}\begin{matrix}x=5\\x=7\end{matrix}\right.\)

\(\left(x-5\right)\left(x-7\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-5=0\\x-7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=5\\x=7\end{matrix}\right.\)

Vậy \(x\in\left\{5;7\right\}\).

= 16 . 5 - [ 131 - 9^2]

= 16 . 5 - [ 131 - 81 ]

= 16 . 5 - 51

= 80 - 51

=29

       A  =   4⁰ + 4¹ + 4²+ 4³ + ....+4²⁰²⁰

      4A  =          4¹ + 4² + 4³ +....+4²⁰²⁰ + 4²⁰²¹

 4A - A  =  4²⁰²¹ -1

       3A =  4²⁰²¹ - 1

        A = (4²⁰²¹ - 1):3

  B - A = 4²⁰²¹ : 3 - (4²⁰²¹ -1) : 3

  B - A = ( 4²⁰²¹ - 4²⁰²¹ + 1): 3

   B - A = 1/3

giúp mik nhanh nha

PQ = 12 cm

Vì theo t/c HBH có 2 cặp cạnh đối // và = nhau

 Học tốt!

\(\dfrac{9}{12}\) và \(\dfrac{7}{15}\)

\(\dfrac{9}{12}=\dfrac{9.15}{12.15}=\dfrac{135}{180}\\ \dfrac{7}{15}=\dfrac{7.12}{15.12}=\dfrac{84}{180}\)

  17 + 3.2³ 

= 17 + 3.8 

= 17 + 24

= 41

(x +1)+(x+3)+(x+5)+.....+(x+55) = 868

(x+1 + x +55){ (x+55 - x - 1) : 2 + 1}: 2 = 868

(2x +56). 28: 2 = 868

(2x + 56 ) = 868 x 2 : 28

2x + 56 = 62

2x = 62 - 56

2x = 6

x = 6 : 2

x = 3