(2 ^ 2 + 1) x (2 ^ 2 - 1) x (2 ^ 4 - 4 ^ 2)

= (2 ^ 2 + 1) x (2 ^ 2 - 1) x (  16  -   16  )

= (2 ^ 2 + 1) x (2 ^ 2 - 1) x 0

= 0

   ( 7 ^ 3 + 7 ^ 5) x (5 ^ 4 + 5 ^ 6) x ( 3 ^ 3 x 3 - 9 ^ 2)

= ( 7 ^ 3 + 7 ^ 5) x (5 ^ 4 + 5 ^ 6) x (    3 ^ 4   - 3 ^ 4)

= ( 7 ^ 3 + 7 ^ 5) x (5 ^ 4 + 5 ^ 6) x 0

= 0

   2 ^ 2 x 5 [( 5 ^ 2 + 2 ^ 3) : 11] - 2 ^ 4 + 2 x 10 ^ 3

=    4   x 5 [(   25  +    8  ) : 11] -    8   + 2 x  1000

=        20  (           33       :  11) -    8   +    2000

=        20 x                 3           -    8    +    2000

=                   60                     -     8    +   2000

=                                 2052

\(a)4(15-18)-(3-5).(-3)^2\)

\(=4.\left(-3\right)-2.9\)

\(=6\)

\(b)(-4-11):(-3)\)

\(=-15:\left(-3\right)\)

\(=5\)

\(c)143-(-57)-(-2)^3.(-3)^0\)

\(=143+57+8.1\)

\(=208\)

\(d,\left(-5\right).\left[\left(90-2.5\right)-10^2+10:\left|-2\right|\right]\)

\(=-5.\left[80-100+10:2\right]\)

\(=-5.-15\)

\(=75\)

\(\Leftrightarrow220+16+x-5=64.5=320\\ \Leftrightarrow231+x=320\\ \Leftrightarrow x=89\)

a: \(\frac{4^5\cdot10\cdot5^6+25^5\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}\)

\(=\frac{2^{10}\cdot2\cdot5\cdot5^6+5^{10}\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}=\frac{2^8\cdot5^7\left(2^3+3^3\right)}{2^5\cdot5^4\left(2^3+3^3\right)}\)

\(=2^3\cdot5^3=10^3=1000\)

b: \(149-\left(35:x+3\right)\cdot17=13\)

=>\(\left(35:x+3\right)\cdot17=149-13=136\)

=>35:x+3=136:17=8

=>35:x=8-3=5

=>\(x=\frac{35}{5}=7\)

c: \(121:11-\left(4x+5:3\right)=4\)

=>11-(4x+5/3)=4

=>4x+5/3=11-4=7

=>\(4x=7-\frac53=\frac{21}{3}-\frac53=\frac{16}{3}\)

=>\(x=\frac{16}{3}:4=\frac43\)

d: \(720:\left\lbrack41-\left(2x-5\right)\right\rbrack=40\)

=>\(41-\left(2x-5\right)=\frac{720}{40}=18\)

=>2x-5=41-18=23

=>2x=28

=>\(x=\frac{28}{2}=14\)

e: Sửa đề: (x+1)+(x+2)+(x+3)+...+(x+100)=5700

=>100x+(1+2+3+...+100)=5700

=>\(100x+100\cdot\frac{101}{2}=5700\)

=>x+50,5=57

=>x=57-50,5

=>x=6,5

5^2x-3 - 2x5² = 5² x 3

5^2x-3 - 2x5² =  75

5^2x-3 - 50 = 75

5^2x-3 = 75 +50

5^2x-3 =  125 = 5³

=>  2x - 3 = 3

=> 2x = 3+3

=> 2x = 6

=>x = 6:2

=> x = 3

tick nhé

bạn nên tự suy nghĩ làm thì hơn

k mk nha!

thanks!

nhanha!!!

C

C

A = \(\dfrac{1}{1\times2}\) + \(\dfrac{3}{2\times5}\) + \(\dfrac{5}{5\times10}\) + \(\dfrac{4}{10\times14}\) + \(\dfrac{6}{14\times20}\)

A = \(\dfrac{1}{1}\) - \(\dfrac{1}{2}\) + \(\dfrac{1}{2}\) - \(\dfrac{1}{5}\) + \(\dfrac{1}{5}\) - \(\dfrac{1}{10}\) + \(\dfrac{1}{10}\) - \(\dfrac{1}{14}\) + \(\dfrac{1}{14}\) - \(\dfrac{1}{20}\)

A = \(\dfrac{1}{1}\) - \(\dfrac{1}{20}\)

A = \(\dfrac{19}{20}\)