Question

tinh nhanh 4 phan 5 cong 2 phan 7 cong 11 phan 5 cong 12 phan 7 cong 1 phan 5

Answer 1

\(\frac{4}{5}+\frac{2}{7}+\frac{11}{5}+\frac{12}{7}+\frac{1}{5}\)

\(=\frac{4}{5}+\frac{11}{5}+\frac{1}{5}+\frac{2}{7}+\frac{12}{7}\)

\(=\frac{4+11+1}{5}+\frac{2+12}{7}\)

\(=\frac{16}{5}+\frac{14}{7}\)

\(=\frac{16}{5}+2=\frac{26}{5}\)

Answer 2

\(\frac{4}{5}+\frac{2}{7}+\frac{11}{5}+\frac{12}{7}+\frac{1}{5}\)

\(=\left(\frac{4}{5}+\frac{11}{5}+\frac{1}{5}\right)+\left(\frac{2}{7}+\frac{12}{7}\right)\)

\(=\frac{16}{5}+\frac{14}{7}\)

\(=\frac{16}{5}+2=\frac{16}{5}+\frac{10}{5}=\frac{26}{5}\)

Answer 3

\(\frac{4}{5}+\frac{2}{7}+\frac{11}{5}+\frac{12}{7}+\frac{1}{5}\)

\(=\left(\frac{4}{5}+\frac{11}{5}+\frac{1}{5}\right)+\left(\frac{2}{7}+\frac{12}{7}\right)\)

\(=\frac{16}{5}+2\)

\(=\frac{26}{5}\)