\(\left(\dfrac{1}{3}\right)^{50}.9^{25}=\left(\dfrac{1}{9}\right)^{25}.9^{25}=\dfrac{1}{9^{25}}.9^{25}=1\)
\(\left(\dfrac{1}{3}\right)^9.9^{25}=\left(\dfrac{1}{9}\right)^{25}.9^{25}=\left(\dfrac{1}{9}.9\right)^{25}=1^{25}=1\)
\(\left(\dfrac{1}{3}\right)^{50}.9^{25}=\left(\dfrac{1}{9}\right)^{25}.9^{25}=\dfrac{1}{9^{25}}.9^{25}=1\)
\(\left(\dfrac{1}{3}\right)^9.9^{25}=\left(\dfrac{1}{9}\right)^{25}.9^{25}=\left(\dfrac{1}{9}.9\right)^{25}=1^{25}=1\)
Tính :
a) \(-\dfrac{3}{4}.31\dfrac{11}{23}-0.75.8\dfrac{12}{23}\)
b) \(\left(2\dfrac{1}{3}+3\dfrac{1}{2}\right):\left(-4\dfrac{1}{6}+3\dfrac{1}{7}\right)+7\dfrac{1}{2}\)
c) \(4\dfrac{5}{9}:\left(\dfrac{-5}{7}\right)+5\dfrac{4}{9}:\left(\dfrac{-5}{7}\right)\)
d) \(4\dfrac{25}{16}+25\left(\dfrac{9}{16}:\dfrac{125}{64}:\dfrac{-27}{8}\right)\)
e) \(\dfrac{2}{3}-4\left(\dfrac{1}{2}+\dfrac{3}{4}\right)\)
a)\(\dfrac{\dfrac{2}{3}-}{\dfrac{8}{3}-}\dfrac{\dfrac{2}{5}+}{\dfrac{8}{5}+}\dfrac{\dfrac{2}{7}-}{\dfrac{8}{7}-}\dfrac{\dfrac{2}{9}+}{\dfrac{8}{9}+}\dfrac{\dfrac{2}{11}}{\dfrac{8}{11}}\)
b)\(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right)\left(\dfrac{1}{4}-1\right)...\left(\dfrac{1}{50}-1\right)\left(\dfrac{1}{51}-1\right)\)
Tính :
\(M=\left[\left(\dfrac{2}{193}-\dfrac{3}{386}\right).\dfrac{193}{17}+\dfrac{33}{34}\right]:\left[\left(\dfrac{7}{2001}+\dfrac{11}{4002}\right).\dfrac{2001}{25}+\dfrac{9}{2}\right]\)
Tính :
a) \(\left(\dfrac{-2}{3}+\dfrac{3}{7}\right):\dfrac{4}{5}+\left(\dfrac{-1}{3}+\dfrac{4}{7}\right):\dfrac{4}{5}\)
b) \(\dfrac{5}{9}:\left(\dfrac{1}{11}-\dfrac{5}{22}\right)+\dfrac{5}{9}:\left(\dfrac{1}{15}-\dfrac{2}{3}\right).\)
Tính \(3\dfrac{17}{24}\)+\(\left(2\dfrac{8}{15}-4\dfrac{8}{15}\right):\left(2\dfrac{11}{30}-\dfrac{11}{30}\right)\)
\(0,5:\sqrt{625}-\sqrt{\dfrac{4}{25}}+0.18\left(\sqrt{1\dfrac{9}{16}}-\sqrt{\dfrac{9}{16}}\right)\)
a) Cho x=3,7. So sánh:
A = [x] + [x+\(\dfrac{1}{5}\)] + [x+\(\dfrac{2}{5}\)] + [x+\(\dfrac{3}{5}\)] + [x+\(\dfrac{4}{5}\)] và B=[5x]
b)Tính [\(\dfrac{100}{3}\)] + [\(\dfrac{100}{3^2}\)] + [\(\dfrac{100}{3^3}\)] + [\(\dfrac{100}{3^4}\)]
c) Tính \(\left[\dfrac{50}{2}\right]+\left[\dfrac{50}{2^2}\right]+\left[\dfrac{50}{2^3}\right]+\left[\dfrac{50}{2^4}\right]+\left[\dfrac{50}{2^5}\right]\)
1,Tính giá trị biểu thức:
a, A=\(\dfrac{7}{35}+\left(-1\dfrac{3}{4}+\dfrac{12}{7}\right)-\left(\dfrac{1}{4}-\dfrac{2}{7}-\dfrac{13}{35}\right)-\dfrac{3}{7}\)
b, B=\(\sqrt{\dfrac{25}{16}-}\dfrac{\left(-3\right)^2}{\left|-4\right|}+\dfrac{\sqrt{\left(-7\right)^2}}{4}-3.\left(\dfrac{5}{2}\right)^2\)
Tính giá trị của các biểu thức A, B, C rồi sắp xếp các kết quả tìm được theo thứ tự từ nhỏ đến lớn :
\(A=\dfrac{2}{3}+\dfrac{3}{4}.\left(\dfrac{-4}{9}\right)\)
\(B=2\dfrac{3}{11}.1\dfrac{1}{12}.\left(-2,2\right)\)
\(C=\left(\dfrac{3}{4}-0,2\right).\left(0,4-\dfrac{4}{5}\right)\)
Tính:
a) \(\dfrac{-3}{4}.\dfrac{12}{-5}.\left(-\dfrac{25}{6}\right);\) b) \(\left(-2\right).\dfrac{-38}{21}.\dfrac{-7}{4}.\left(-\dfrac{3}{8}\right);\)
c) \(\left(\dfrac{11}{12}:\dfrac{33}{16}\right).\dfrac{3}{5};\) d) \(\dfrac{7}{23}.\left[\left(-\dfrac{8}{6}\right)-\dfrac{45}{18}\right].\)