= ( 10/15-7/15 ) : ( 10/15 - 6/15)2
= 3/15 : (4/15)2 = 3/15 . (15/4)2
= (3.152)/(15.42) rút gọn 15 trên và dưới
= (3.15)/42 =45/16
1. Tính nhanh giá trị biểu thức:
A = \(\dfrac{1}{3}-\dfrac{3}{5}+\dfrac{5}{7}-\dfrac{7}{9}+\dfrac{9}{11}-\dfrac{5}{7}+\dfrac{3}{5}-\dfrac{9}{11}\)
B = \(\dfrac{1}{5}-\dfrac{2}{7}-\left(-\dfrac{2}{3}\right)+\dfrac{1}{42}-\dfrac{1}{4}-\dfrac{13}{28}+\dfrac{2}{15}\)
C = \(\dfrac{1}{50}-\dfrac{1}{50.49}-\dfrac{1}{49.48}-...-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
D = \(\dfrac{0,75-0,6+\dfrac{3}{7}+\dfrac{3}{13}}{2,75-2,2+\dfrac{11}{7}+\dfrac{11}{3}}\)
Tìm x biết
a) \(\dfrac{-2}{5}+\dfrac{5}{3}\left(\dfrac{3}{2}-\dfrac{4}{15}x\right)=\dfrac{-7}{6}\)
b) \(\left(\dfrac{1}{4}x-1\right)+\left(\dfrac{2}{3}x-2\right)-\left(\dfrac{5}{8}x+1\right)=5\)
Ai nhanh 3 tick nha
câu 1 . Thực hiện phép tính
a. 0,05 + 5 - \(\dfrac{1}{2}\)
b. \(\dfrac{6}{15}-\dfrac{7}{8}+3-\dfrac{3}{5}-\dfrac{2}{16}\)
c. \(\dfrac{3}{5}.\dfrac{15}{7}-\dfrac{15}{7}.\dfrac{8}{5}\)
d. \(\dfrac{2}{5.7}+\dfrac{2}{7.9}+\dfrac{2}{9.11}+....+\dfrac{2}{93.99}\)
e. \(\dfrac{7}{4}:\dfrac{-9}{8}-\dfrac{3}{9}\)
f. \(\dfrac{15}{17}.\dfrac{19}{21}+\dfrac{19}{21}.\dfrac{2}{17}+\dfrac{13}{21}\)
g. \(\left(4-\dfrac{5}{12}\right):2+\dfrac{5}{24}\)
tính: A = \(\dfrac{15}{34}+\dfrac{27}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)
B = \(16\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)-28\dfrac{2}{7}:\left(-\dfrac{3}{5}\right)\)
1 thực hiện phép tính(tính nhanh nếu có thể)
\(\left(7\dfrac{1}{3}-\dfrac{1}{3}\right):\dfrac{1}{7}\)
\(\dfrac{-1}{3}.\left(\dfrac{-15}{17}\right).\dfrac{34}{45}\) c,\(\dfrac{1}{2}.\dfrac{6}{5}-\dfrac{1}{5}.\dfrac{1}{2}\)
1.thực hiện phép tính
a.\(\dfrac{-5}{21}-\dfrac{1}{3}+3\dfrac{1}{2}.\left(\dfrac{-2}{3}\right)^3\)
b)\(-2\dfrac{1}{3}+\left(\dfrac{3}{8}-\dfrac{3}{4^{^{ }}}\right)^3:\dfrac{5}{9}-\dfrac{1}{2}\)
c)\(\left(6-2\dfrac{4}{5}\right).3\dfrac{1}{8}-1\dfrac{3}{5}:\left(-\dfrac{1}{2}\right)^2\)
d)\(-\dfrac{3}{7}.\dfrac{5}{9}+\dfrac{4}{7}.\dfrac{-1}{3}-\left(0,5\right)^3\)
e)\(\dfrac{15}{5}-\dfrac{2}{17}+\dfrac{15}{23}-\dfrac{15}{17}+\dfrac{4}{19}\)
Giúp mik nha mai mik phải nộp bài cho thầy rùi nì
\(\dfrac{-1}{3}+\dfrac{2}{5}:\dfrac{-4}{15}+\left(\dfrac{-5}{4}\right).\dfrac{4}{3}:\left(\dfrac{-7}{2}\right)\)
cm:
\(\dfrac{3}{1^2.2^2}+\dfrac{7}{3^2.4^2}+\dfrac{11}{5^2.6^2}+\dfrac{15}{7^2.8^2}+\dfrac{19}{9^2.10^2}< 1\)
bài 1: tính
a) \(\dfrac{5^4.20^4}{25^5.4^5}\) b)3,5-\(\left(-\dfrac{2}{7}\right)\) c)\(\left(\dfrac{11}{12}:\dfrac{33}{16}\right).\dfrac{3}{5}\) d)\(15.\left(-\dfrac{2}{3}\right)^2.-\dfrac{7}{3}\) e)\(\left(\dfrac{9}{25}-2.8\right):\left(3\dfrac{4}{5}+0,2\right)\) g)\(\dfrac{21}{47}+\dfrac{9}{45}+\dfrac{26}{47}+\dfrac{4}{5}\) h)\(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\) j)12.\(\left(-\dfrac{2}{3}\right)^2+\dfrac{4}{3}\) k)\(\dfrac{13}{25}+\dfrac{6}{41}-\dfrac{38}{25}+\dfrac{35}{41}-\dfrac{1}{2}\) l)12,5.\(\left(-\dfrac{5}{7}\right)+1,5.\left(-\dfrac{5}{7}\right)\) m)\(\sqrt{\dfrac{64}{25}}.3\dfrac{1}{2}-\dfrac{3}{5}.3\dfrac{1}{2}\)