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\(A=\left(-\dfrac{5}{7}+\dfrac{8}{5}\right):\dfrac{91}{8}+\left(-\dfrac{2}{7}-\dfrac{3}{5}\right):\dfrac{91}{8}\)
\(=\dfrac{31}{35}:\dfrac{91}{8}+\dfrac{-31}{35}:\dfrac{91}{8}\)
\(=\dfrac{248}{3185}+\dfrac{-248}{3185}\)
= 0
\(B=\dfrac{13}{15}:\left(\dfrac{4}{5}-\dfrac{3}{7}\right)+\dfrac{13}{15}:\left(\dfrac{2}{5}-\dfrac{1}{9}\right)\)
\(=\dfrac{13}{15}:\dfrac{13}{35}+\dfrac{13}{15}:\dfrac{13}{45}\)
\(=\dfrac{7}{3}+3\)
\(=\dfrac{16}{3}\)
Toàn câu dễ nên bạn tự làm đi.
Trong lúc bạn đánh xong bài này thì bạn có thể làm xong rồi đó.
Đừng có ỷ lại vào người khác ,động não lên.
a/ \(\left(-52\right)^3:13^3=\left(-52:13\right)^3=\left(-4\right)^3\)
b/ \(\left(\dfrac{1}{2}\right)^{15}:\left(\dfrac{1}{4}\right)^6=\left(\dfrac{1}{2}\right)^{15}:\left(\dfrac{1}{2}\right)^{12}=\left(\dfrac{1}{2}\right)^3\)
c/ \(\left(\dfrac{1}{9}\right)^{30}:\left(\dfrac{1}{3}\right)^{56}=\left(\dfrac{1}{3}\right)^{60}:\left(\dfrac{1}{3}\right)^{56}=\left(\dfrac{1}{3}\right)^4\)
d/ \(\left(\dfrac{1}{8}\right)^5:\left(\dfrac{1}{16}\right)^3=\left(\dfrac{1}{2}\right)^{15}:\left(\dfrac{1}{2}\right)^{12}=\left(\dfrac{1}{2}\right)^3\)
Tính
a) (- 52)3 : 133 = (- 52 : 13)3 = (- 4)3 = - 64
b) \(\left(\dfrac{1}{2}\right)^{15}:\left(\dfrac{1}{4}\right)^6\)
\(=\left(\dfrac{1}{2}\right)^{15}:\left[\left(\dfrac{1}{2}\right)^2\right]^6\)
\(=\left(\dfrac{1}{2}\right)^{15}:\left(\dfrac{1}{2}\right)^{12}\)
\(=\left(\dfrac{1}{2}\right)^3\)
\(=\dfrac{1}{8}\)
c) \(\left(\dfrac{1}{9}\right)^{30}:\left(\dfrac{1}{3}\right)^{56}\)
\(=\left[\left(\dfrac{1}{3}\right)^2\right]^{30}:\left(\dfrac{1}{3}\right)^{56}\)
\(=\left(\dfrac{1}{3}\right)^{60}:\left(\dfrac{1}{3}\right)^{56}\)
\(=\left(\dfrac{1}{3}\right)^4\)
\(=\dfrac{1}{81}\)
d) \(\left(\dfrac{1}{8}\right)^5:\left(\dfrac{1}{16}\right)^3\)
\(=\left[\left(\dfrac{1}{2}\right)^3\right]^5:\left[\left(\dfrac{1}{2}\right)^4\right]^3\)
\(=\left(\dfrac{1}{2}\right)^{15}:\left(\dfrac{1}{2}\right)^{12}\)
\(=\left(\dfrac{1}{2}\right)^3\)
\(=\dfrac{1}{8}.\)
a: \(A=\dfrac{3^6\cdot3^8\cdot5^4-3^{13}\cdot5^{13}\cdot5^{-9}}{3^{12}\cdot5^6+5^6\cdot3^{12}}\)
\(=\dfrac{3^{14}\cdot5^4-3^{13}\cdot5^4}{2\cdot3^{12}\cdot5^6}\)
\(=\dfrac{3^{13}\cdot5^4\cdot\left(3-1\right)}{2\cdot3^{12}\cdot5^6}=\dfrac{3}{5^2}=\dfrac{3}{25}\)
c: \(C=\dfrac{\dfrac{27}{64}+\dfrac{125}{64}-5\cdot\dfrac{16-15}{12}}{\dfrac{25}{64}+\dfrac{4}{9}-\dfrac{5}{6}}\)
\(=\dfrac{47}{24}:\dfrac{1}{576}=47\cdot24=1128\)
làm bài 3 BĐT
theo bảng xét dấu
còn bài 1,2 ở trên là 1.1 và 1.2 đều trg bài 1.2
bài 1.2 (tức bài 2 ở trên )làm a,b,c,d
\còn bài 2( tức bài 2 ở trên) làm hết
\(\left(\dfrac{1}{5}+\dfrac{5}{6}-\dfrac{9}{10}\right).\dfrac{3}{5}-0,75:1\dfrac{1}{2}-1,25^2\)
\(=\left(\dfrac{1}{5}+\dfrac{5}{6}-\dfrac{9}{10}\right).\dfrac{3}{5}-\dfrac{3}{4}:\dfrac{3}{2}-\dfrac{25}{16}\) \(=\left(\dfrac{31}{30}-\dfrac{9}{10}\right).\left(-\dfrac{3}{20}\right):\left(-\dfrac{1}{16}\right)\\ \\ \\ \\ \\ \\ \\ \\ \\ =\dfrac{2}{15}.\left(-\dfrac{3}{20}\right):\left(-\dfrac{1}{16}\right)\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ =\left(-\dfrac{1}{50}\right):\left(-\dfrac{1}{16}\right)\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ =\dfrac{8}{25}\)
Bạn tính hai vế à.!? Hay tính vế thứ nhất rồi với vế thứ 2.!???
f, \(\dfrac{2^9.4^{10}}{8^8}=\dfrac{2^9.\left(2^2\right)^{10}}{\left(2^3\right)^8}=\dfrac{2^9.2^{20}}{2^{24}}=\dfrac{2^{29}}{2^{24}}=2^5=32\)
a: \(=\left(\dfrac{1}{3}-\dfrac{4}{3}\right)+\dfrac{14}{25}+\dfrac{11}{25}+\dfrac{2}{7}=\dfrac{2}{7}\)
b: \(=\dfrac{3}{7}-\dfrac{5}{2}-\dfrac{3}{5}+\dfrac{4}{7}+\dfrac{3}{2}-\dfrac{2}{5}=1-1-1=-1\)
c: \(=\dfrac{4}{25}+\dfrac{7}{5}\cdot\dfrac{5}{2}-2=\dfrac{4}{25}+\dfrac{7}{2}-2=\dfrac{83}{50}\)
\(\left(\dfrac{-2}{3}\right)^3:\left(\dfrac{-2}{3}\right)^2+\dfrac{2^{40}\cdot3^{29}}{8^{13}\cdot9^{15}}\)
\(=\dfrac{-2}{3}+\dfrac{2^{40}\cdot3^{29}}{\left(2^3\right)^{13}\cdot\left(3^2\right)^{15}}\)
\(=\dfrac{-2}{3}+\dfrac{2^{40}\cdot3^{29}}{2^{39}\cdot3^{30}}\)
\(=\dfrac{-2}{3}+\dfrac{2}{3}\)
\(=0\)
\(Toru\)