thuc hien phep tinh:
\(\frac{-1}{12}\)-(\(2\frac{5}{8}\)-\(\frac{1}{3}\))
thuc hien phep tinh
\(\frac{6}{7}+\frac{1}{7}.\frac{2}{7}+\frac{1}{7}.\frac{5}{7}\)
\(\frac{6}{7}+\frac{1}{7}.\frac{2}{7}+\frac{1}{7}.\frac{5}{7}=\frac{6}{7}+\frac{2}{14}+\frac{5}{14}=\frac{12}{14}+\frac{7}{14}=\frac{19}{14}\)
Thuc hien phep tinh:
a/\(\frac{\frac{1}{9}-\frac{1}{7}-\frac{1}{11}}{\frac{4}{9}-\frac{4}{7}-\frac{4}{11}}\)+ \(\frac{0,6-\frac{3}{25}-\frac{3}{125}-\frac{3}{625}}{\frac{4}{5}-0,16-\frac{4}{125}-\frac{4}{625}}\)
b/ \(\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\frac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
giúp tui với : -8 . 25 . ( -2 ) . ( -25 ) .4 .125
Thuc hien phep tinh \(\frac{5}{4-\sqrt{11}}+\frac{1}{3+\sqrt{7}}-\frac{6}{\sqrt{7}-2}-\frac{\sqrt{7}-5}{2}\)
Thuc hien phep tinh
a) \(\frac{-5}{9}+\frac{8}{15}+\frac{-2}{11}+\frac{4}{-9}+\frac{7}{15}\)
b) \(\left(3\frac{2}{5}+2\frac{3}{4}\right)-4\frac{2}{5}\)
-5/9+8/15+-2/11+-4/9/7/17
(-5/9+-4/9)+(8/15+7/15+-2/11
-1+1+-2/11
-2/11
(17/5+11/4)-22/5
123/20-22/5
123/20-88/20
35/20
Thuc hien phep tinh
c) \(\left(5\frac{2}{3}-4\frac{5}{6}\right)+1\frac{1}{6}\)
d) \(9\frac{5}{13}-\left(\frac{2}{5}+4\frac{5}{13}\right)\)
Thuc hien phep tinh :
\(\frac{3^8.16^2}{12^4.8^3}\)
38.162/124.83
= 38.(24)2/(22.3)4.(23)3
= 38.28/28.34.29
=34/29
=81/512
\(\frac{3^8\cdot16^2}{12^4\cdot8^3}\)
\(=\frac{3^8\cdot2^8}{3^4\cdot2^8\cdot2^9}\)
\(=\frac{81}{512}\)
\(=\frac{3^8.\left(2^4\right)^2}{\left(3.4\right)^4.\left(2^3\right)^3}=\frac{3^8.2^8}{3^4.\left(2^2\right)^4.2^9}=\frac{3^4}{2^9}=\frac{81}{512}\)
Khong thuc hien phep tinh de tim ket qua.Hay chung minh rang cac tong sau lon hon 1
M = \(\frac{3}{7}+\frac{3}{8}+\frac{3}{10}\)
thuc hien phep tinh :
\(\frac{1}{x-1}-\frac{x^3-x}{x^2+1}\left(\frac{1}{x^2-2x+1}+\frac{1}{1-x^2}\right)\)
thuc hien phep tinh \(\frac{4x-8}{x+5}\)* \(\frac{25-x^2}{2x-x^2}\)
\(\frac{4x-8}{x+5}\)* \(\frac{25-x^x}{2x-x^2}\)
\(=\)\(\frac{4\left(x-2\right)\left(5-x\right)\left(5+x\right)}{\left(x+5\right)x\left(2-x\right)}\)
\(=\)\(\frac{-4\left(5-x\right)}{x}\)\(=\)\(\frac{x-20}{x}\)