1: \(=\dfrac{3^{28}}{3^{12}\cdot3^{18}}=\dfrac{1}{9}\)
2: \(=\dfrac{2^3\cdot3^3\cdot3^{10}}{2^3\cdot3^{12}}=3\)
3: \(=\dfrac{7^6\cdot3^{10}}{3^5\cdot7^7}=\dfrac{3^5}{7}\)
Thuc hien phep tinh;
a/ \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
b/ \(\left(\dfrac{1}{25}+\dfrac{1}{5}+1\right):\left(\dfrac{1}{25}-\dfrac{1}{5}-1\right)\)
c/ \(\dfrac{\dfrac{1}{9}-\dfrac{1}{7}-\dfrac{1}{11}}{\dfrac{4}{9}-\dfrac{4}{7}-\dfrac{4}{11}}\)+ \(\dfrac{0,6-\dfrac{3}{25}-\dfrac{3}{125}-\dfrac{3}{625}}{\dfrac{4}{5}-0,16-\dfrac{4}{125}-\dfrac{4}{625}}\)
d/ \(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
\(E=\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{7}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
Tính :
\(E=\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{7}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
Bài 1:So sánh
a,\(\left(-50\right)^{20}\)và \(2550^{10}\)
b, \(\left(-999\right)^{10}\)và \(999999^5\)
Bài 2:Tìm x thuộc Z để :\(\dfrac{x}{9}\)<\(\dfrac{4}{7}\)<\(\dfrac{x+1}{9}\)
Bài 3:Tìm cặp số nguyên a,b sao cho;
a,\(\dfrac{b}{5}\)+\(\dfrac{1}{10}\)=\(\dfrac{1}{a}\)
b, \(\dfrac{a}{4}\)-\(\dfrac{1}{2}\)=\(\dfrac{3}{b}\)
Bài 4:Rút gọn:
M=\(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125:7\right)^9+5^9:\left(14\right)^3}\)
A = \(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^3+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
giải giúp mk nha mn! thk nhìu nhìu
Bài 1 : Tính
a) \(\dfrac{1}{3}.\dfrac{-4}{5}+\dfrac{1}{3}.\dfrac{-6}{5}\)
b) \(\dfrac{3}{7}.\dfrac{9}{26}-\dfrac{1}{14}.\dfrac{1}{13}\)
tìm x biết
1) \(\dfrac{2}{3}+\dfrac{1}{3}:x=\dfrac{3}{5}\)
2) \(\left(\dfrac{2x}{3}-3\right):\left(-10\right)=\dfrac{2}{5}\)
3) \(2\dfrac{2}{3}:x=2\dfrac{1}{12}:\left(-0,06\right)\)
4) \(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14}\)
5) \(-\dfrac{3}{5}.x-\dfrac{1}{2}=-\dfrac{1}{7}\)
6) \(\dfrac{1}{5}+2x=-2\dfrac{1}{4}\)
7)\(-\dfrac{1}{2}:x=\dfrac{3}{8}:\dfrac{9}{16}\)
8)\(\dfrac{2}{3}:x=2\dfrac{1}{2}:\left(-0,3\right)\)
9) \(\dfrac{x}{3}=\dfrac{-2}{1,5}\)
Tìm y biết :
a) \(-\dfrac{3}{5}.y=\dfrac{21}{10}\)
b) \(y:\dfrac{3}{8}=-1\dfrac{31}{33}\)
c) \(1\dfrac{2}{5}.y+\dfrac{3}{7}=-\dfrac{4}{5}\)
d) \(-\dfrac{11}{12}.y+0,25=\dfrac{5}{6}\)
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) \(\left(-\dfrac{1}{3}\right)^2.\dfrac{4}{11}+\dfrac{7}{11}.\left(-\dfrac{1}{3}\right)^2\)
Tìm y, biết:
a) \(-\dfrac{3}{5}\times y=\dfrac{21}{10}\)
b) \(y\div\dfrac{3}{8}=-1\dfrac{31}{33}\)
c) \(1\dfrac{2}{5}\times y+\dfrac{3}{7}=-\dfrac{4}{5}\)
d) \(-\dfrac{11}{12}\times y+0,25=\dfrac{5}{6}\)
