Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a)=27+65+346-27-65
=(27-27)+(65-65)+346
=0+0+346
=346
b)=42+69-17-42+17-35
=(42-42)+(17-17)+(69-35)
=0+0+34
=34
\(4^{2019}-4^{2018}-4^{2017}-...-4-1\)
Đặt \(A=1+4+...+4^{2017}+4^{2018}+4^{2019}\)
\(\Leftrightarrow4A=4+4^2+...+4^{2018}+4^{2019}+4^{2020}\)
\(\Rightarrow4A-A=4^{2020}-1\)
\(\Rightarrow3A=4^{2020}-1\Leftrightarrow A=\frac{4^{2020}-1}{3}\)
\(\Leftrightarrow-A=\frac{1-4^{2020}}{3}\)
Vậy ....
a,2.8.5.25.125.4
=(8.125)(4.25)(2.5)
=1000.100.10=1000000
b,-25.3.9.(-4)
=[-25.(-4)](3.9)
=100.27=2700
a) ( 2.5) . ( 8.125 ) . ( 25.4 ) = 10 . 1000 . 100 = 1000000
b) [ -25.(-4) ] . 3 . 9 = ( 25 . 4 ) . 27 = 100 . 27 = 2700
35 . 18 - 5 . 7 . 28
= 35 . 18 - ( 5 . 7 ) . 28
= 35 . 18 - 35 . 28
= 35 . ( 18 - 28 )
= 35 . ( - 10 )
= - 350
35.18-5.7.28
=35.18-35.28
=35.(18-28)
=35.(-10)
=-350
k minh nhe ban !
341.67+341.16+659.83
= 341.(67+16)+659.83
=341.83+659.83
=83.(341+659)
=83.1000
=83000
341.67+341.16+659.83
=(341.67+341.16)+659.83
=341.(67+16)+659.83
=341.83+659.83
=83.(341+659)
=83.1000
=83000
5/15.16+5/16.17+5/17.18+5/18.19+5/19.20
=5(1/15-1/16+1/16-1/17+..+1/19-1/20)
=5.(1/15-1/20)
=5.1/60
=1/12
\(\frac{5}{15.16}+\frac{5}{16.17}+\frac{5}{17.18}+\frac{5}{18.19}+\frac{5}{19.20}\)
= \(5.\left(\frac{1}{15.16}+\frac{1}{16.17}+\frac{1}{17.18}+\frac{1}{18.19}+\frac{1}{19.20}\right)\)
= \(5.\left(\frac{1}{15}-\frac{1}{16}+\frac{1}{16}-\frac{1}{17}+\frac{1}{17}-\frac{1}{18}+\frac{1}{18}-\frac{1}{19}+\frac{1}{19}-\frac{1}{20}\right)\)
= \(5.\left(\frac{1}{15}-\frac{1}{20}\right)\)
= \(5.\frac{1}{60}\)
= \(\frac{1}{12}\)
nhanh nhé các bạn
35.18-5.7.35
= 35.18 - 35.35
= 35. ( 18-35)
= 35. (-17)
=-595