=(2,75-2,25)-0.6=0,5-0,6=-0,1

Ngon thí

mấy bài này 2 phần đầu ko tính hợp lí đc

a) \(=10\frac{1}{4}\cdot\frac{-5}{3}-8\frac{1}{4}\cdot\frac{-5}{3}-5=\left(10\frac{1}{4}-8\frac{1}{4}\right)\cdot\frac{-5}{3}-5\)

\(=\left(\frac{41}{4}-\frac{33}{4}\right)\cdot\frac{-5}{3}-5=2\cdot\frac{-5}{3}-5\)\(=\frac{-10}{3}-\frac{15}{3}=\frac{-25}{3}\)

b)\(=\frac{5}{7}+1+\frac{2}{7}+\frac{2^{10}\cdot\left(2^3\right)^3}{\left(2^2\right)^9}\)

\(=\frac{5}{7}+\frac{2}{7}+1+\frac{2^{10}\cdot2^9}{2^{27}}\)

\(=1+1+\frac{1}{2^8}=2+\frac{1}{256}=\frac{512}{256}+\frac{1}{256}=\frac{513}{256}\)

=14/25+1/3+2/7-4/3+11/25

=(14/25+11/25)+(1/3-4/3)+2/7

=1+(-1)+2/7

=0+2/7

=2/7

a. \(-\frac{13}{6}:\frac{25}{7}+\frac{7}{25}.\left(-\frac{17}{6}\right)\)

\(=-\frac{13}{6}.\frac{7}{25}+\frac{7}{25}.\left(-\frac{17}{6}\right)\)

\(=\frac{7}{25}.\left[\left(-\frac{13}{6}\right)+\left(-\frac{17}{6}\right)\right]\)

\(=\frac{7}{25}.\left(-\frac{30}{6}\right)\)

\(=-\frac{7}{5}\)

b. \(\frac{-4^5.3^5}{2^4.6^4}+2015^0=\frac{\left(-4.3\right)^5}{\left(2.6\right)^4}+1=\frac{-12^5}{12^4}+1=-12+1=-11\)

a) \(\frac{-13.7}{6.25}\)+ \(\frac{-7.17}{25.6}\)=\(\frac{-210}{210}\)=-1

b) \(\frac{-4^4.4.3^4.3}{2^4.3^4.2^4}\)=\(\frac{-2^4.2^4.4.3^4.3}{2^4.3^4.2^4}\)=-12

Jdkdk

Jidkri

2n là số chính phương ---> 
n=2k²\(\Rightarrow\)3n=6k²
3n là số lập phương Suy ra 6=k.a³
n nhỏ nhất suy ra a=1 ---> k=6 ---> n=72[/QUOTE]

\(\frac{15\frac{1}{4}}{-\frac{5}{7}}-\frac{25\frac{1}{4}}{-\frac{5}{7}}=\frac{15\frac{1}{4}-25\frac{1}{4}}{-\frac{5}{7}}=\frac{-10}{-\frac{5}{7}}=10\cdot\frac{7}{5}=14\)

đáp án 14 là đúng