Question

giúp mình với!

​Tính nhanh

15 * 14+30/15*14+60

​0,1:3+0,2:3+0,3:3+0,4:3+0,5:3

​ cảm ơn.

​

​

Answer 1

\(\frac{15\times14+30}{15\times14+60}\)

\(=\frac{14\times15+30}{15\times14+60}\)

\(=\frac{30}{60}=\frac{1}{2}\)

Answer 2

\(0,1:3+0,2:3+0,3:3+0,4:3+0,5:3\)

\(=3:\left(0,1+0,2+0,3+0,4+0,5\right)\)

\(=3:\left(\frac{1}{10}+\frac{2}{10}+\frac{3}{10}+\frac{4}{10}+\frac{5}{10}\right)\)

\(=3:\left(\frac{1+2+3+4+5}{10}\right)\)

\(=3:\frac{3}{2}\)

\(=\frac{3\times2}{3}\)

\(=\frac{1\times2}{1}\)

\(=\frac{2}{1}\)