\(A=\frac{3}{2^2}.\frac{8}{3^2}.\frac{15}{4^2}...\frac{899}{30^2}=\frac{1.3.2.4.3.5...29.31}{2.2.3.3.4.4...30.30}=\frac{\left(2.3...29.30\right).\left(3.4.5...29.31\right)}{\left(2.3...29.30\right).\left(2.3.4...29.30\right)}=\frac{31}{2.30}=\frac{31}{60}\)
xin chào mọi người
Rút gọn
\(\frac{3}{2^2}.\frac{8}{3^2}.\frac{15}{4^2}......\frac{899}{30^2}\)
Hộ!
Tính hợp lí:
a) \(\frac{-8}{15}.\left(-30\right).\left(\frac{15}{-8}\right).\frac{9}{10}\)
b) \(2\frac{1}{18}.\frac{23}{24}.\frac{9}{37}.\frac{48}{-15}\)
c) A=\(\frac{-0,8+\frac{4}{7}+\frac{4}{9}}{0,3.\frac{3}{14}-\frac{3}{18}}+\frac{0,23-3,5+\frac{2}{7}}{0,69-10,5+\frac{6}{7}}\)
4.Tinh
a,\(\frac{4^{30}.3^{43}}{2^{53}.27^{15}}\)
b,\(\frac{\left(-27\right)^{10}.16^{25}}{6^{30}.\left(-32\right)^{15}}\)
c,\(\left(\frac{-2}{17}\right)^3.\left(\frac{-17}{35}\right)^3.\left(\frac{35}{3}\right)^3\)
d,\(\frac{3^{31}.25^8-9^{14}.5^{15}}{27^{10}.5^{15}-3^{30}.5^{17}}\)
e,\(2^{^2}+4^{^2}+6^2+..........+24^2\left(1^2+2^2+3^2+....+12^2=650\right)\)
Tính : A = \(\dfrac{\dfrac{1}{14}-\dfrac{1}{30}-\dfrac{1}{46}}{\dfrac{2}{35}-\dfrac{2}{75}-\dfrac{2}{115}}\):\(\frac{\frac{3}{8}-\frac{15}{17}+\frac{30}{31}}{\frac{1}{6}-\frac{20}{51}+\frac{40}{93}}\)
giúp mình với
1, tính
a, \(2^5+8\left[\left(-2\right)^3:\frac{1}{2}\right]^0-\left(\frac{1}{2}\right)^3\times2+\left(-2\right)^3\)
b, \(\frac{7}{15}-\frac{9}{19}-\frac{-8}{15}-\frac{10}{19}\)
c, \(1\frac{1}{3}:\frac{4}{5}+2\frac{2}{3}:\frac{4}{5}\)
Tính giá trị biểu thức
\(1.A=\frac{1}{5}+\frac{3}{17}-\frac{4}{3}+\left(\frac{4}{5}-\frac{3}{17}+\frac{1}{3}\right)-\frac{1}{7}+\left[\frac{-14}{30}\right]\)
\(2.B=\left(\frac{5}{8}-\frac{4}{12}+\frac{3}{2}\right)-\left(\frac{5}{8}+\frac{9}{13}\right)-\left[\frac{-3}{2}\right]+\frac{7}{-15}\)
\(3.C=\frac{5}{18}+\frac{8}{19}-\frac{7}{21}+\left(\frac{-10}{36}+\frac{11}{19}+\frac{1}{3}\right)-\frac{5}{8}\)
\(4.D=\frac{1}{9}-\left[\frac{-5}{23}\right]-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{14}-\frac{7}{30}\)
\(5.E=\frac{1}{13}+\left(\frac{-5}{18}-\frac{1}{13}+\frac{12}{17}\right)+\left(\frac{12}{17}+\frac{5}{18}+\frac{7}{5}\right)\)
\(6.F=\frac{15}{14}-\left(\frac{17}{23}-\frac{80}{87}+\frac{5}{4}\right)+\left(\frac{12}{17}-\frac{15}{14}+\frac{1}{4}\right)\)
\(7.G=\frac{1}{25}-\frac{4}{27}+\left(\frac{-23}{27}+\frac{-1}{25}-\frac{5}{43}\right)+\frac{5}{43}-\frac{4}{7}\)
\(8.H=\frac{4}{15}-\frac{23}{28}-\left(\frac{-23}{28}+\frac{-11}{15}-\frac{29}{27}\right)-\frac{2}{27}\)
\(9.K=\frac{1}{16}-\frac{5}{21}+\left(\frac{-1}{16}+\frac{-3}{5}-\frac{-5}{21}\right)+\frac{-2}{5}+\frac{3}{4}\)
\(10.L=\frac{7}{12}+\frac{15}{14}-\left(\frac{14}{22}+\frac{-1}{14}+\frac{5}{21}\right)-\frac{-5}{21}+\frac{3}{5}\)
Tính \(\frac{2^2}{3}.\frac{3^2}{8}.\frac{4^2}{15}...\frac{9^2}{80}\)
\(\frac{15^8.9^7}{27^7.25^4}=\)
\(\frac{9^3}{\left(3^4-3^3\right)^2}=\)
\(\left(\frac{1}{2}-\frac{2}{3}+\frac{3}{4}-\frac{2}{5}\right):x=\frac{11}{30}\)
\(\frac{-3}{4}.x+0,7.x=1,25:\frac{1}{8}\)
1. Thực hiện phép tính
a, \(\frac{25^{15}.4^{15}}{5^{17}.20^{16}}\)
2 Tìm x
\(\frac{-x}{2}=\frac{8}{-x}\)
b, \(\left(\frac{3}{4}\right)^{2x}:\left(\frac{2}{5}\right)^{10}=\left(\frac{15}{8}\right)^{10}\)
3. Tính diện tích của mảnh vườn HCN, biết tỉ lệ giữa chiều rộng và chiều dài bằng 0,25 và chu vi của mảnh vườn đó là 120m
