K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

31 tháng 12 2022

a)= 2021.2021-2020.(2021+1)
  = 2021.(2020+1)-2020.(2021+1)
  = (2021.2020)+2021-(2020.2021)-2020
  = 1

31 tháng 12 2022

b) B= (1+2-3-4)+(5+6-7-8)+(9+10-11-12)...........+(2017+2018-2019-2020)+2021
    B= -4+(-4)+....................(-4)+2021
    B= -4x505+2021
    B= -2020 + 2021
    B = 1

a: \(A=21\cdot100-11\cdot100+90\cdot100+100\cdot125\cdot16\)

\(=100\left(21-11+90\right)+100\cdot2000\)

\(=100\left(10+90+2000\right)=2100\cdot100=210000\)

b: \(=\dfrac{5\cdot2^{30}\cdot3^{18}-2^{29}\cdot3^{20}}{5\cdot2^{28}\cdot3^{19}-7\cdot2^{29}\cdot3^{18}}\)

\(=\dfrac{2^{29}\cdot3^{18}\left(5\cdot2-3^2\right)}{2^{28}\cdot3^{18}\left(5\cdot3-7\cdot2\right)}=2\)

 

27 tháng 8 2023

\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)  (sửa \(-9^9\rightarrow.9^9\))

\(=\dfrac{5.2^{30}.3^{18}-2^2.3^{20}.2^{27}}{5.2^9.2^{19}.3^{19}-7.2^{29}.3^{18}}\)

\(=\dfrac{5.2^{30}.3^{18}-2^{29}.3^{20}}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}\)

\(=\dfrac{2^{29}.3^{18}\left(15-9\right)}{2^{28}.3^{18}\left(15-14\right)}\)

\(=2.6=12\)

11 tháng 6 2021

Bạn cho mình hỏi là 5.4 vs mấy cái tương tự là 5 nhân 4 hay 5,4 vậy?

11 tháng 6 2021

5 nhân 4 

Lớp sáu như thế mà

12 tháng 1 2018

\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}=\dfrac{5.2^{30}.3^{18}-2^2.3^{20}.2^{27}}{5.2^9.2^{19}.3^{19}-7.2^{29}.3^{18}}=\dfrac{2^{29}.3^{18}\left(5.2-3^2\right)}{2^{28}.3^{18}\left(5.3-7.2\right)}=\dfrac{2^{29}.3^{18}}{2^{28}.3^{18}}=\dfrac{2^{29}}{2^{28}}=2^1=2\)

13 tháng 1 2018

có câu hỏi đâu bạn!

Sửa đề:\(\dfrac{5\cdot4^{15}\cdot9^9-4\cdot3^{20}\cdot8^9}{5\cdot2^9\cdot6^{19}-7\cdot2^{29}\cdot27^6}\)

\(=\dfrac{5\cdot2^{30}\cdot3^{18}-3^{20}\cdot2^{29}}{5\cdot2^9\cdot3^{19}\cdot2^{19}-7\cdot2^{29}\cdot3^{18}}\)

\(=\dfrac{3^{18}\cdot2^{29}\cdot\left(5\cdot2-9\right)}{2^{28}\cdot3^{18}\cdot\left(5\cdot3-7\cdot2\right)}=2\)

3 tháng 6 2018

Xét tử :

5.415.99 - 4.320.89

= 5.230.318 - 22 . 320 . 227

= 5 . 230 . 318 - 229 . 320

= 318 . 220 . ( 5 . 210 - 29 . 32 )

= 318 . 220 . [ 29 . ( 5 . 2 - 32 ) ]

= 318 . 220 . 29

= 318 . 229

Xét mẫu :

5.29.619 - 7.229.276

= 5 . 2. 219 . 319 - 7 . 229 . 318

= 5 . 228 . 319 - 7 . 229 . 318

= 318 . 228 . ( 5 . 3 - 7 . 2 )

= 318 . 228

B = \(\frac{3^{18}.2^{29}}{3^{18}.2^{28}}=2\)

7 tháng 7 2017

\(A=\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{7.2^{29}.27^6-5.2^9.6^{19}}\)

\(A=\dfrac{5.2^{30}.3^{18}-2^2.3^{20}.2^{27}}{7.2^{29}.3^{18}-5.2^9.2^{19}.3^{19}}\)

\(A=\dfrac{2^{29}.3^{18}.\left(5.2-3^2\right)}{2^{28}.3^{18}.\left(7.2-5.3\right)}\)

\(A=\dfrac{2.\left(10-9\right)}{14-15}=\dfrac{2}{-1}=-2\)

Chúc bạn học tốt!!!

7 tháng 7 2017

\(A=\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{7.2^{29}.27^6-5.2^9.6^{19}}=\dfrac{5.\left(2^2\right)^{15}.\left(3^2\right)^9-2^2.3^{20}.\left(2^2\right)^9}{7.2^{29}.27^6-5.2^9.\left(2.3\right)^{19}}\)

\(=\dfrac{5.2^{30}.3^{18}-2^2.3^{20}.2^{27}}{7.2^{29}.3^{18}-5.2^9.2^{19}.3^{19}}\)

\(=\dfrac{2^{29}.3^{18}\left(5.2-3^2\right)}{2^{28}.3^{18}\left(7.2-5.3\right)}\)

\(=\dfrac{2\left(10-9\right)}{14-15}=\dfrac{2}{-1}=-2\)

5 tháng 1 2019

\(B=\frac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)

   \(=\frac{5.2^{30}.3^{18}-2^2.3^{20}.2^{27}}{5.2^9.2^{19}.3^{19}-7.2^{29}.3^{18}}\)

   \(=\frac{2^{29}.3^{18}\left(5.2-3^2\right)}{2^{28}.3^{18}\left(5.3-7.2\right)}\)

   \(=\frac{2^{29}.3^{18}.1}{2^{28}.3^{18}.1}\)

   \(=2\)

\(=\dfrac{5\cdot2^{30}\cdot3^{18}-2^{29}\cdot3^{20}}{5\cdot2^{29}\cdot3^{19}-7\cdot2^{29}\cdot3^{18}}=\dfrac{2^{29}\cdot3^{18}\left(5\cdot2-3^2\right)}{2^{29}\cdot3^{18}\left(5\cdot3-7\right)}=\dfrac{10-9}{15-7}=\dfrac{1}{8}\)