\(=\dfrac{2^3}{2^5}\cdot\dfrac{3^5}{3^7}\cdot\dfrac{5^7}{5^5}=\dfrac{1}{4\cdot9}\cdot25=\dfrac{25}{36}\)
\(=\dfrac{2^3}{2^5}\cdot\dfrac{3^5}{3^7}\cdot\dfrac{5^7}{5^5}=\dfrac{1}{4\cdot9}\cdot25=\dfrac{25}{36}\)
Thực hiện phép tính (bằng cách hợp lí nếu có thể)
a) \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
b) \(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}.33\dfrac{1}{3}\)
c) \(9.\left(\dfrac{1}{3}\right)^3+\dfrac{1}{3}\)
d) \(15\dfrac{1}{4}:\left(-\dfrac{5}{7}\right)-25\dfrac{1}{4}:\left(-\dfrac{5}{7}\right)\)
Bài 1:
a) Thực hiện phép tính: \(\dfrac{17}{13}\)-\(\dfrac{5}{3}\)
b) Cho tam giác ABC có góc A=70o và gócB=65o . Tính số đo của góc C.
Bài 2:
a) Tìm x biết: \(x+3\dfrac{1}{2}=\dfrac{11}{5}\)
b) Vẽ đồ thị của hàm số y = 3x
c) Tính nhanh: \(\left(\dfrac{-3}{7}+\dfrac{5}{11}\right):\dfrac{4}{31}+\left(\dfrac{-4}{7}+\dfrac{6}{11}\right):\dfrac{4}{31}\)
Câu 1.Thực hiện phép tính:
a) -1\(\dfrac{5}{7}.15+\dfrac{2}{7}.\left(-15\right)+\left(-105\right).\left(\dfrac{2}{3}-\dfrac{4}{5}+\dfrac{1}{7}\right)\)
b) \(\dfrac{2^{15}.9^4}{6^6.8^3}\)
thực hiện phép tính (tính hợp lí nếu có thể)
1) \(-0,75.\dfrac{12}{-5}.4\dfrac{1}{6}.\left(-1\right)^2\)
2) \(\dfrac{11}{25}.\left(-24,8\right)-\dfrac{11}{25}.75,2\)
3) \(\left(-\dfrac{3}{4}+\dfrac{2}{7}\right):\dfrac{2}{3}+\left(-\dfrac{1}{4}+\dfrac{5}{7}\right):\dfrac{2}{3}\)
4) \(\left(\dfrac{1}{2}-\dfrac{2}{3}\right)-\left(\dfrac{5}{3}-\dfrac{3}{2}\right)+\left(\dfrac{7}{3}-\dfrac{5}{2}\right)\)
5) \(\left(-2\right)^2+\sqrt{36}-\sqrt{9}+\sqrt{25}\)
6) \(\left(-\dfrac{1}{3}\right)^2.\dfrac{4}{11}+\dfrac{7}{11}.\left(-\dfrac{1}{3}\right)^2\)
Thực hiện phép tính
a, \(\dfrac{5}{16}\)+\(\dfrac{1}{12}-\dfrac{7}{8}\)
b,\(\dfrac{5}{17}+\dfrac{8}{9}+\dfrac{17}{17}-\)0,7\(-1\dfrac{8}{9}\)
c,\((1-\dfrac{1}{2})^2-(-\dfrac{1}{3})^2:\dfrac{1}{3}+\dfrac{\sqrt{64}}{4}\)
d,\(15\dfrac{1}{4}:(-\dfrac{5}{7})-25\dfrac{1}{4}:(-\dfrac{5}{7})\)
Bài 1: Thực hiên phép tính:
a) \(\dfrac{1}{99.97}-\dfrac{1}{97.95}-\dfrac{1}{95.93}-...-\dfrac{1}{5.3}-\dfrac{1}{3.1}\)
b)\(\dfrac{\dfrac{3}{7}-\dfrac{3}{11}+\dfrac{3}{13}}{\dfrac{5}{7}-\dfrac{5}{11}+\dfrac{5}{13}}+\dfrac{\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{4}}{\dfrac{5}{4}-\dfrac{5}{6}+\dfrac{5}{8}}\)
Thực hiện phép tính:(hợp lý nếu có thể)
a, \(5.\dfrac{5}{27}+\dfrac{7}{23}+0,5.\dfrac{5}{7}+\dfrac{16}{23}+\dfrac{1}{2}\)
b, \(25\dfrac{1}{6}:\dfrac{-4}{5}-45\dfrac{1}{6}:\dfrac{-4}{5}\)
c, \(25.\left(\dfrac{-1}{5}\right)^3+\dfrac{1}{5}-2.\left(\dfrac{-1}{2}\right)^2-\dfrac{1}{2}\)
d, \(-\left(251.3+281\right)+3.251-\left(1-281\right)\)
e, \(\left(0,75-\dfrac{1}{4}\right):\left(-5\right)+\dfrac{1}{15}-\left(-\dfrac{1}{5}\right):\left(-3\right)\)
f, \(\sqrt{\dfrac{4}{81}}:\sqrt{\dfrac{25}{81}}-1\dfrac{2}{5}\)
Bài 2 khó hơn nè : Thực hiện phép tính:
a, \(\dfrac{3}{5}+\dfrac{2}{7}
\)
b , \(\dfrac{-4}{3}:\dfrac{2}{15}\)
c, \(\dfrac{3}{7}.\dfrac{2}{9}+\dfrac{7}{9}.\dfrac{3}{7}\)
d, \(\left(\dfrac{-2}{3}\right)^3.9^2+\left(\dfrac{-3}{4}\right)^2.32\)
Thực hiện phép tính:
a) \(\dfrac{25^7.125^5}{5^{28}}\)
b) (2\(\dfrac{1}{4}\)+2,5):(-3\(\dfrac{1}{6}\)+2\(\dfrac{1}{7}\))