Question

1: Tính:

a) 1 + 1/3 + 1/9 + 1/27 + 1/81

b) 37.52 + 4.7 * 2 .3 -9.8

 

Answer 1

\(1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}\)

\(=\frac{1}{1}+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}\)

\(=\frac{81}{81}+\frac{27}{81}+\frac{9}{81}+\frac{3}{81}+\frac{1}{81}\)

\(=\frac{121}{81}\)

Answer 2

37,52 + 4,7 x 2,3 - 9,8

= 37,52 + 10,81 - 9,8

= 26,71 - 9,8

= 16,91

Answer 3

\(1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}\)

\(=1+\frac{27}{81}+\frac{9}{81}+\frac{3}{81}+\frac{1}{81}\)

\(=\frac{81}{81}+\frac{27}{81}+\frac{9}{81}+\frac{3}{81}+\frac{1}{81}\)

\(=\frac{121}{81}\)

Answer 4

\(37,52+4,7\times2,3-9,8\)

\(=37,52+10,81-9,8\)

\(=26,71-9,8\)

\(=16,91\)