81

3⁴=3x3x3x3=9x3x3=27x3=81 

giúp mình với 

bạn chia nhỏ câu hỏi ra đi ạ

Viết lại hộ mik cái

Ko nhìn đc bn ui!@##

bạn viết gì vậy

Từ đề bài tả có :

gọi số hs lớp 6a là : a; gọi số hs lớp 6b là:b

24 + 11.(a-1) = 23 + 10.(b-1)

24 + 11a - 11 = 23 + 10b - 10

13 + 11a = 13 + 10b11a = 10b200 < 13+11a < 300
17 < a < 26

200 < 13 + 10b < 300

18 < b < 28

b = 11a/10

b = 1,1a
a = 20

b = 22

Ta có: 

Đa thức: \(f\left(x\right)=ax^2+bx+c\) ⋮ 5

\(\Rightarrow f\left(x\right)=5\cdot\left(\dfrac{a}{5}x^2+\dfrac{b}{5}x+\dfrac{c}{5}\right)\) ⋮ 5

\(\Rightarrow a,b,c\in B\left(5\right)\) 

Vậy khi f(x) chia hết cho 5 thì a,b,c chia hết cho 5

f=84[05\66\ơ515[52[ư4[\

7;ơ4411[ư1[5

4

4['\

vì

ik

k\uyke]

'uy

'^k''m '\7ys'tfdh'se\ử'ý'0rtư

\(\left(-\dfrac{3}{4}+\dfrac{2}{5}\right):\dfrac{2}{7}+\left(\dfrac{3}{5}+\dfrac{1}{4}\right):\dfrac{3}{7}\)

\(=\left(-\dfrac{15}{20}+\dfrac{8}{20}\right):\dfrac{2}{7}+\left(\dfrac{12}{20}+\dfrac{5}{20}\right):\dfrac{3}{7}\)

\(=\left(-\dfrac{7}{20}\right):\dfrac{2}{7}+\dfrac{17}{20}:\dfrac{3}{7}\)

\(=-\dfrac{7}{20}.\dfrac{7}{2}+\dfrac{17}{20}.\dfrac{7}{3}\)

\(=\dfrac{7}{20}\left(-\dfrac{7}{2}+\dfrac{17}{3}\right)\)

\(=\dfrac{7}{20}\left(-\dfrac{21}{6}+\dfrac{34}{6}\right)\)

\(=\dfrac{7}{20}.\dfrac{13}{6}\)

\(=\dfrac{91}{120}\)

( -3/4 + 2/5 ) : 2/7 + ( 3/5 + 1/4 ) : 3/7 = 91/120

\(\dfrac{3}{7}.\dfrac{9}{36}-\dfrac{1}{14}.\dfrac{1}{13}\)

\(=\dfrac{3.9}{7.36}-\dfrac{1.1}{14.13}\)

\(=\dfrac{3}{28}-\dfrac{1}{182}=\dfrac{37}{364}\)

3/7 . 9/36 - 1/14 . 1/13

= 3/28 - 1/182 

= 37/364

\(A=\left(7-\dfrac{3}{4}+\dfrac{1}{3}\right)-\left(6+\dfrac{5}{4}-\dfrac{4}{3}\right)-\left(5-\dfrac{7}{4}+\dfrac{5}{3}\right)\)

\(\Rightarrow A=7-\dfrac{3}{4}+\dfrac{1}{3}-6-\dfrac{5}{4}+\dfrac{4}{3}-5+\dfrac{7}{4}-\dfrac{5}{3}\)

\(\Rightarrow A=\left(7-6-5\right)-\dfrac{3}{4}-\dfrac{5}{4}+\dfrac{7}{4}+\dfrac{1}{3}+\dfrac{4}{3}-\dfrac{5}{3}\)

\(\Rightarrow A=-4-\dfrac{1}{4}+0\)

\(\Rightarrow A=-\dfrac{17}{4}\)

Cách 2 tính trong dấu ngoặc đơn của A, bạn tự tính nhé.

A = -17/4

\(Ư\left(48\right)=\left\{1;-1;-2;2;3;-3;6;-6;8;-8;12;-12;-24;24;16;-16;48;-48\right\}\\ Ư\left(8\right)=\left\{1;-1;2;-2;-4;4;8;8\right\}\\ Ư\left(14\right)=\left\{-1;1;2;-2;7;-7;14;-14\right\}\\ Ư\left(20\right)=\left\{-1;1;2;-2;5;-5;4;-4;-10;10;-20;20\right\}\)