\(\dfrac{-1}{39}+\dfrac{-1}{52}=\dfrac{-4-3}{156}=-\dfrac{7}{156}\)

\(\dfrac{-52}{2028}+\dfrac{-39}{2028}=\dfrac{-7}{156}\)

\(=\dfrac{-4}{156}-\dfrac{3}{156}=\dfrac{-7}{156}\)

t 0 co bt

?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????/??bố thằng nào mà biết được

\(\frac{\frac{1}{9}-\frac{1}{39}+\frac{1}{63}}{\frac{1}{12}-\frac{1}{52}+\frac{1}{84}}=\frac{\frac{1}{3}\left(\frac{1}{3}-\frac{1}{13}+\frac{1}{21}\right)}{\frac{1}{4}\left(\frac{1}{3}-\frac{1}{13}+\frac{1}{21}\right)}=\frac{1}{3}:\frac{1}{4}=\frac{4}{3}\)

\(\frac{-1}{39}+\frac{-1}{52}=\frac{-4}{156}+\frac{-3}{156}=\frac{-7}{156}\)

bài này quá dễ

quy đồng ra là tính thôi :>

@Khanh Nguyễn Ngọc

bn lm nhanh ghê rứa? :v

\(A=\left[6.\left(\frac{1}{3}\right)^3-3\left(\frac{-1}{3}\right)+1\right]:\left(\frac{-1}{3}-1\right)\)

\(A=\left[6.\frac{1}{27}-3.\left(\frac{-1}{3}\right)+1\right]:\left(\frac{-1}{3}-1\right)\)

\(A=\left[\frac{2}{9}-\frac{-3}{3}+\frac{9}{9}\right]:\left(\frac{-1}{3}+\frac{-3}{3}\right)\)

\(A=\frac{2}{9}.\frac{-3}{4}=\frac{1}{3}.\frac{-1}{2}=\frac{-1}{6}\)

\(a,\\ 52^2+52.48=52.52+52.48=52.\left(52+48\right)=52.100=5200\\ b,\\ 39^2-39.29=39.39-39.29=39.\left(39-29\right)=39.10=390\\ c,\\ 99.5^3+125=99.125+125=125.\left(99+1\right)=125.100=12500\)

a) 52² + 52 . 48 = 2704 + 2496 = 5200

b) 39² - 39 . 29 = 1521 - 1131 = 390

c) 99 . 5³ + 125 = 99 . 125 + 125 = 12375 + 125 = 12400

bạn tham khảo nha

a)  85 .12,7 + 5.3.12,7 = 12,7 . ( 85 + 5.3 ) = 12,7 . (85+15) = 12,7 . 100 = 1270

b)  52.143 - 52.39 - 8.26 = 52.143 - 52.39 - 4.2.26 = 52.143 - 52.39 - 4.52 = 52.( 143 -39 - 4 ) = 52 . 100 = 5200

phân tích :

5x - 20y = 5 .(x - 4y)

5x(x-1)-3x.(x-1) = (x-1).(5x-3x) = 2x(x-1)  hoặc 5x(x-1)-3x(x-1) = x(x-1)(5-3) = 2x(x-1)

x.(x+y)-5x-5y = x(x+y) - 5 (x+y) = (x+y)(x-5)