\(695-\left[200+\left(11-1^2\right)\right]\\ =695-\left[200+\left(11-1\right)\right]\\ =695-\left(200+10\right)\\ =695-210\\ =485\)

= 695 - [200 + 10² ]

= 695 - 300

=395

\(129-5\left[29\left(6-1^2\right)\right]\)

\(=129-5\left[29\left(6-1\right)\right]\)

\(=129-5\left(29\cdot5\right)\)

\(=129-5\cdot145\)

\(=129-725\)

\(=-596\)

\(...=129-5\left(29.5\right)=129-725=-596\)

\(659-\left[200+\left(17-7^2\right)\right]\)

\(=659-\left[200+\left(17-49\right)\right]\)

\(=659-\left(200-42\right)\)

\(=659-158\)

\(=501\)

Ta có: \(30+18=48\) 

Vậy \(48\) chia cho \(30\) được số dư là \(18\)

Số chia cho 30 được số dư là 18 là \(a=30.r+18\left(r=1,2...\right)\)

\(\Rightarrow a\in\left\{48;78;108;138;...\left(30r+18\right)\right\}\)

1) \(2^8.4.16.32.64.2=2^8.2^2.2^4.2^5.2^6.2=2^{8+2+4+5+6+1}=2^{26}\)

2) \(7.3^x-11=52\Rightarrow7.3^x=52+11=63\)

\(\Rightarrow3^x=63:7=9\Rightarrow3^x=3^2\Rightarrow x=2\)

\(4^{10\left(x+5\right)}=4^{12}\Rightarrow10\left(x+5\right)=12\)

\(\Rightarrow10x+50=12\Rightarrow10x=12-50=-38\)

\(\Rightarrow x=-38:10=-\dfrac{38}{10}=-\dfrac{19}{5}\)

\(7x-2x=6^{17}:6^{15}+2^8:2^6\)

\(\Rightarrow5x=6^2+2^2\Rightarrow5x=36+4=40\)

\(\Rightarrow x=40:5=8\)

\(3^{2x-1}=27\Rightarrow3^{2x-1}=3^3\Rightarrow2x-1=3\)

\(\Rightarrow2x=4\Rightarrow x=4:2=2\)

1) 2⁸. 4 . 16 . 32 . 64

= 2⁸. 2². 2⁴. 2⁵. 2⁶

= 2²⁵

\(66a+39b+63c\)

\(=3\left(22a+13b+21c\right)⋮3\)

Vậy tổng trên có chia hết cho 3

66a  + 39b + 63c 

3. 22 . a + 3. 13 . b + 3 . 31 . c 

3 (22a + 13b + 31c ) chia hết cho 3 

suy ra 66a + 39b + 63c chia hết cho 3 

Ư(10) = {\(\pm\)1; \(\pm\)2; \(\pm\)5; \(\pm\)10}

⇒ 3x - 5 \(\in\) {-10; -5; -2; -1; 1; 2; 5; 10}

⇒ x \(\in\) {\(\dfrac{-5}{3}\); 0; 1; \(\dfrac{4}{3}\); 2; \(\dfrac{10}{3}\); 5}

  A= 1 + 5 + 5² + 5 ³ + ... + 5⁸⁰⁰ 

5A=       5 + 5²  + 5³ + .... +5 ⁸⁰⁰ + 5⁸⁰¹  

5A - A = 5⁸⁰¹  - 1 

4a = 5⁸⁰¹ - 1 

    5⁸⁰¹ - 1 +1 = 5ⁿ

⇒  5⁸⁰¹ = 5ⁿ ⇒ n = 801

   \(\dfrac{4}{9}\) : \(\left(-\dfrac{1}{7}\right)\) + \(6\dfrac{5}{9}\) + \(6\dfrac{5}{19}\) : \(\left(-\dfrac{1}{7}\right)\)

= \(\dfrac{4}{9}\) . \(\left(-\dfrac{7}{1}\right)\) + \(\dfrac{59}{9}\) + \(\dfrac{119}{19}\) . \(\left(-\dfrac{7}{1}\right)\)

= \(\dfrac{-28}{9}\) + \(\dfrac{59}{9}\) + \(\dfrac{-833}{19}\)

= \(\dfrac{31}{9}\) + \(\dfrac{-833}{19}\)

= \(\dfrac{589}{171}\) + \(\dfrac{-7497}{171}\)

= \(\dfrac{-6908}{171}\)

nhanh

Em nên dùng công thức toán học để mọi người hiểu đề cho đúng

em ko bt cách ghi mũ kiểu gì ạ