\(\left(3^{15}.4+5.3^{15}\right):3^{16}=3^{15}.\left(4+5\right):3^{16}=3^{15}.9:3^{16}=3^{15}.3^2:3^{16}=3^{15+2-16}=3^1=3\)

\(\frac{-1}{-16}-\frac{1}{15}\)

\(=\frac{1}{16}-\frac{1}{15}\)

\(=\frac{15-16}{16\times15}\)

\(=\frac{-1}{240}\)

c. ơn bn nha

\(\frac{-1}{-16}\)-\(\frac{1}{15}\)

=\(\frac{1}{16}\)-\(\frac{1}{15}\)

=\(\frac{15}{240}\)-\(\frac{16}{240}\)

=\(\frac{15-16}{240}\)

=\(\frac{-1}{240}\)

\(-\frac{1}{16}-\frac{1}{15}\)

\(=-\left(\frac{1}{16}+\frac{1}{15}\right)\)

\(=-\frac{16+15}{16\times15}\)

\(=-\frac{31}{240}\)

31/240

đó bạn

\(-\frac{1}{16}-\frac{1}{15}=\frac{-15}{240}-\frac{16}{240}=\frac{-15-16}{240}=\frac{-31}{240}\)

M=20/112+20/280+20/520+20/832

M=20/8.14+20/14.20+20/26.20+20/26.32

M=20/6.(6/8.14+6/14.20+6/20.26+6/26.32)

M=20/6.(1/8-1/14+1/14-1/20+1/20-1/26+1/26-1/32)

M=20/6.(1/8-1/32)

M=20/6.3/32

M=5/16

\(M=\frac{20}{112}+\frac{20}{280}+\frac{20}{520}+\frac{20}{832}\)

\(M=\frac{20}{8.14}+\frac{20}{14.20}+\frac{20}{20.26}+\frac{20}{26.32}\)

\(M=\frac{20}{6}\left(\frac{6}{8.14}+\frac{6}{14.20}+\frac{6}{20.26}+\frac{6}{26.32}\right)\)

\(M=\frac{10}{3}.\left(\frac{1}{8}-\frac{1}{14}+\frac{1}{14}-\frac{1}{20}+\frac{1}{20}-\frac{1}{26}+\frac{1}{26}-\frac{1}{32}\right)\)

\(M=\frac{10}{3}.\left(\frac{1}{8}-\frac{1}{32}\right)\)

\(M=\frac{10}{3}.\left(\frac{4}{32}-\frac{1}{32}\right)\)

\(M=\frac{10}{3}.\frac{3}{32}\)

\(M=\frac{5}{16}\)

Chúc bạn học tốt !!!! 

25-[50-(2^3.17-2^3.14)]

=25-[50-(8.17-8.14)]

=25-[50-(136-112)]

=25-[50-24]

=25-26

=-1

|-128|: [45^2-(2010-2008.1^2010)]

=128:[45^2-(2010-2008.1)]

=128:[45^2-(2010-2008)]

=128:[45^2-2]

=128:[2025-2]

=128:2023

=0,063 (chắc mik làm sai b đấy :(  )

25-[50-(2^3.17-2^3.14)]=25-{50-[2^3.(17-14)]}

                                     =25-{50-[8.3]}

                                     =25-{50-24}

Thực hiện phép tính:

2 : 1/2 = 4

tích mik nha

=4

ai k mk mk

lại cho ng đó !

2 : 1/2 = 4

tích mik ủng hộ nha 

do thu ha

1>    Theo de bai, ta co     \(452-32⋮a\)

                              \(\Rightarrow420⋮a\)(1)

                                           \(321-21⋮3\)

                              \(\Rightarrow300⋮a\)(2)

 Tu (1)(2)  \(\Rightarrow a\in U\left(420,300\right)\)sao cho\(a\in N\)

                      \(a=60\)

2> Ta co  \(\left(3^{15}\cdot4+5\cdot3^{15}\right)\div3^{15}\)

\(\Rightarrow3^{15}\cdot\left(4+5\right)\div3^{15}\)

\(=9\)

bạn ấy làm đúng r

Bn Anh Le oi, mk gui nham Cau 1

Rút gọn phân số rồi tính như thường :)

\(-\frac{9991}{9992}+\frac{1}{99}-\frac{2}{19984}-\frac{5}{495}\)

\(=-\frac{9991}{9992}+\frac{1}{99}-\frac{1}{9992}-\frac{1}{99}\)

\(=\left(-\frac{9991}{9992}-\frac{1}{9992}\right)+\left(\frac{1}{99}-\frac{1}{99}\right)\)

\(=-1+0\)

\(=-1\)

a) 341 . 67 + 341 . 16 + 659 . 83

= 341 . (67 + 16) + 659 . 83

= 341 . 83 + 659 . 83

= 83 .( 341+659)

= 83 . 1000 = 83000

b) 42 .53+ 47 . 156 -47 . 114

= 42 . 53 + 47. ( 156 -114)

=42 . 53 + 47 . 42

= 42 .(53 +47)

= 42 .100 =4200

a, \(341.67+341.16+659.83\)

\(=341\left(67+16\right)+659.83\)

\(=341.83+659.83\)

\(=83\left(341+659\right)\)

\(=83.1000=83000\)

b, \(42.53+47.156-47.114\)

\(=42.53+47\left(156-114\right)\)

\(=42.53+47.42\)

\(=42\left(53+47\right)\)

\(=42.100=4200\)

   Chúc bạn học tốt!

a $341.67+341.16+659.83$

$=341\left(67+16\right)+659.83$

$=341.83+659.83$

$=83\left(341+659\right)$

$=83.1000=83000$

b, $42.53+47.156-47.114$

$=42.53+47\left(156-114\right)$

$=42.53+47.42$

$=42\left(53+47\right)$

$=42.100=4200$