\(\text{a) }\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)\\ =\dfrac{3\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)}{3}\\ =\dfrac{\left(2^2-1\right)\left(2^2+1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)}{3}\\ \\ =\dfrac{\left(2^4-1\right)\left(2^4+1\right)\left(2^8+1\right)\left(2^{16}+1\right)}{3}\\ =\dfrac{\left(2^8-1\right)\left(2^8+1\right)\left(2^{16}+1\right)}{3}\\ =\dfrac{\left(2^{16}-1\right)\left(2^{16}+1\right)}{3}\\ =\dfrac{2^{32}-1}{3}\\ \)

\(\text{b) }24\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\\ =\left(5^2-1\right)\left(5^2+1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right)\\ =\left(5^4-1\right)\left(5^4+1\right)\left(5^8+1\right)\left(5^{16}+1\right) \\ =\left(5^8-1\right)\left(5^8+1\right)\left(5^{16}+1\right)\\ =\left(5^{16}-1\right)\left(5^{16}+1\right)\\ =5^{32}-1\\ \)

\(\text{c) }48\left(7^2+1\right)\left(7^4+1\right)\left(7^8+1\right)\left(7^{16}+1\right)\\ =\left(7^2-1\right)\left(7^2+1\right)\left(7^4+1\right)\left(7^8+1\right)\left(7^{16}+1\right)\\ =\left(7^4-1\right)\left(7^4+1\right)\left(7^8+1\right)\left(7^{16}+1\right)\\ =\left(7^8-1\right)\left(7^8+1\right)\left(7^{16}+1\right)\\ =\left(7^{16}-1\right)\left(7^{16}+1\right)\\ =7^{32}-1\)

Đề là gì vậy bạn?

Giải chi tiết cho mình nha

\(\dfrac{2}{5}+\dfrac{11}{15}=\dfrac{6}{15}+\dfrac{11}{15}=\dfrac{17}{15}\)

\(\dfrac{7}{8}-\dfrac{7}{9}=\dfrac{63}{72}-\dfrac{56}{72}=\dfrac{7}{72}\)

\(\dfrac{11}{13}\times\dfrac{26}{31}=\dfrac{22}{31}\)

\(\dfrac{16}{24}:4=\dfrac{16}{24}\times\dfrac{1}{4}=\dfrac{4}{24}=\dfrac{1}{6}\)

\(30:\dfrac{6}{5}=30\times\dfrac{5}{6}=25\)

\(\dfrac{9}{16}:4=\dfrac{9}{16}\times\dfrac{1}{4}=\dfrac{9}{64}\)

\(\dfrac{1}{2}:\dfrac{1}{3}\times\dfrac{8}{15}=\dfrac{1}{2}\times3\times\dfrac{8}{15}=\dfrac{4}{5}\)

2/5 + 11/15 = 17/15
7/8 - 7/9 = 7/72
11/13 x 26/31 = 22/31
16/24 : 4 = 1/6
30 : 6/5 = 25
9/16 : 4 = 9/64
1/2 : 1/3 x 8/15 = 3/2 x 8/15 = 4/5

\(1\frac{1}{2}+x=\frac{3}{2}-7\)

<=> \(\frac{3}{2}+x=\frac{-11}{2}\)

<=> \(x=-7\)

\(\frac{1}{4}+\frac{1}{3}:3x=-5\)

<=> \(\frac{1}{3}:3x=\frac{-21}{4}\)

<=> \(3x=\frac{-4}{63}\)

<=> \(x=\frac{4}{189}\)

\(\frac{4}{5}.x=\frac{8}{35}\)

<=> \(x=\frac{2}{7}\)

\(\frac{2}{3x}-\frac{1}{4}=\frac{7}{1}\)

<=> \(\frac{2}{3x}=\frac{29}{4}\)

=> \(8=87x\)

<=> \(x=\frac{8}{87}\)

\(\frac{3}{5x}+\frac{1}{2}=\frac{1}{7}\)

<=> \(\frac{3}{5x}=\frac{-5}{14}\)

<=> \(-25x=42\)

<=> \(x=\frac{-42}{25}\)

\(1-\left(5\frac{3}{8}+x-7\frac{5}{24}\right):\left(-16.\frac{2}{3}\right)=0\)

<=> \(1-\left(\frac{43}{8}+x-\frac{173}{24}\right):\frac{-32}{3}=0\)

<=> \(\frac{43}{8}+x-\frac{173}{24}=\frac{-32}{3}\)

<=> \(\frac{43}{8}+x=\frac{-83}{24}\)

<=> \(x=\frac{-53}{6}\)

học tốt

a.1/4 +3/8 +5/16=15/16

b, 3/5 - 1/3 -1/6=1/10

c, 4/7 *5/8 *7/12=5/24

d. 25/28 : 15/24 * 6/7=60/49

Ghi đầy đủ nha

bn có thể ghi rõ ràng đc ko?

a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\) 

=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\) 

=\(0+\dfrac{5}{13}\) 

=\(\dfrac{5}{13}\)

Ta có: \(8\left(7^8+1\right)\left(7^4+1\right)\left(7^2+1\right)=\frac{1}{6}.48\left(7^2+1\right)\left(7^4+1\right)\left(7^8+1\right)\)

\(=\frac{1}{6}\left(7^2-1\right)\left(7^2+1\right)\left(7^4+1\right)\left(7^8+1\right)\)

\(=\frac{1}{6}\left(7^4-1\right)\left(7^4+1\right)\left(7^8+1\right)\)

\(=\frac{1}{6}\left(7^8-1\right)\left(7^8+1\right)\)

\(=\frac{1}{6}\left(7^{16}-1\right)\)

Vì  \(7^{16}-1>\frac{1}{6}\left(7^{16}-1\right)\) nên  \(7^{16}-1>8\left(7^8+1\right)\left(7^4+1\right)\left(7^2+1\right)\)

Bài 1: 

1: =-5/24+16/27+3/4

=-5/24+18/24+16/27

=13/24+16/27

=117/216+128/216=245/216

2: =-1/3+1/3+6/7=6/7

3: \(=\dfrac{1}{2}-\dfrac{7}{12}+\dfrac{1}{2}=1-\dfrac{7}{12}=\dfrac{5}{12}\)

4: \(=-\dfrac{5}{8}+\dfrac{14}{25}-\dfrac{6}{10}=\dfrac{-125+112-120}{200}=\dfrac{-133}{200}\)

A) 137/ 12

B) 4

C) 5

b, 3/5 + 4/7 + 2/8 + 10/25 + 9/21 + 28/16

= 3/5 + 4/7 + 2/8 + 2/5 + 3/7 + 14/8

= (3/5 + 2/5) + ( 4/7 + 3/7) + ( 2/8 + 14/8)

= 1 + 1 + 7/4

= 2 + 7/4 = 15/4

c , 8/7 + 7/6 + 5/8 + 10/12 + 24/28 + 6/16 

= c , 8/7 + 7/6 + 5/8 + 5/6 + 6/7 + 1/2

= (8/7 + 6/7) + (7/6 + 5/6) + 5/8 + 1/2

= 14/7 + 12/6 + 5/8 + 1/2

= 2 + 2 + 5/8 + 1/2

= 4 + 9/8 = 41/8