a) \(259.\left(13+86+1\right)=259.100=25900\)

a/ 259 . 13 + 259 . 86 + 259

= 259 . 13 + 259 . 86 + 259 . 1

= 259 . ( 13 + 86 + 1 )

= 259 . 100

= 25 900

1. Tính theo cách hợp lí:

\(2016.5^{2017}.\left(30.5^{2015}-5^{2016}\right)\)

\(=2016.5^{2017}.5^{2015}.\left(30-5\right)\)

\(=2016.5^{4032}.25\)

\(=2016.5^{4032}.5^2\)

\(=2016.5^{4034}\)

2. Tìm x:

\(4^{x+1}+4^0=65\)

\(\Leftrightarrow4^{x+1}+1=65\)

\(\Leftrightarrow4^{x+1}=65-1\)

\(\Leftrightarrow\left(2^2\right)^{x+1}=64\)

\(\Leftrightarrow2^{2x+2}=2^6\)

\(\Rightarrow2x+2=6\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=2.\)

a, (5/7+ 2/7) + ( 3/8+5/8)

= 1              + 1

\(;l\\ 54\backslash54\)

a) 1007-0/2=503.5

b)

D. Tìm x thuộc Z biết 

x+(x+1)+(x+2)+....+2016+2017=2017 

=> ( x + x + x + ..+ x ) + ( 1 + 2 + 3+...+2016 + 2017 ) = 2017 

<=> 2017x + 2035153 = 2017 

=> 2017x = -2033136

=> x = -1008

Vậy ...

cảm ơn bạn nhưng bạn có biết những câu hỏi còn lại ko

\(\dfrac{10.4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}=\dfrac{5.2.2^{12}.3^{10}+3^9.2^9.2^3.3.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)

\(=\dfrac{5.2^{13}.3^{10}+2^{12}.3^{10}.5}{2^{11}.3^{11}\left(2.3-1\right)}=\dfrac{2^{12}.3^{10}.5\left(2+1\right)}{2^{11}.3^{11}.5}\)

\(=\dfrac{2^{11}.2.3^{10}.5.3}{2^{11}.3^{10}.3.5}=2\)

Bài 2: 

\(B=\dfrac{2^{15}\cdot5^8-2^5\cdot2^9\cdot5^9}{2^{16}\cdot5^7+2^{16}\cdot5^8}=\dfrac{2^{14}\cdot5^8\left(2-5\right)}{2^{16}\cdot5^7\left(1+5\right)}=\dfrac{5}{4}\cdot\dfrac{-3}{6}=\dfrac{5}{4}\cdot\dfrac{-1}{2}=-\dfrac{5}{8}\)