Question

Rút gọn rồi tính 

a,3/9+9/15+8/12

b,4/10+12/32+9/15

 

Answer 1

A, 3/9 + 9/15 + 8/12

= 1/3 + 9/15 + 2/3

= 8/5

B, 4/10 + 12/32 + 9/15

= 2/5 + 3/8 + 9/15

= 11/8

Answer 2

A) 3/9+9/15+8/12

=1/3+3/5+2/3

=1+3/5

=8/5

Answer 3

\(\frac{3}{9}+\frac{9}{15}+\frac{8}{12}=\frac{1}{3}+\frac{3}{5}+\frac{2}{3}\)

                                \(=\frac{5}{15}+\frac{9}{15}+\frac{10}{15}\)   

                                  \(=\frac{24}{15}=1\frac{9}{15}=1\frac{3}{5}=1,6\)   

\(\frac{4}{10}+\frac{12}{32}+\frac{9}{15}=\frac{2}{5}+\frac{3}{8}+\frac{3}{5}\)

                                 \(=\frac{16}{40}+\frac{15}{40}+\frac{24}{40}\)

                                   \(=\frac{55}{40}=1\frac{15}{40}=1,375\)

Answer 4

\(a.\frac{3}{9}+\frac{9}{15}+\frac{8}{12}\\ =\frac{1}{3}+\frac{3}{5}+\frac{2}{3}\\ =\frac{5}{15}+\frac{9}{15}+\frac{10}{15}\\ =\frac{5+9+10}{15}\\ =\frac{24}{15}\\ =\frac{8}{5}\)

\(b.\frac{4}{10}+\frac{12}{32}+\frac{9}{15}\\ =\frac{2}{5}+\frac{3}{8}+\frac{3}{5}\\ =\frac{16}{40}+\frac{15}{40}+\frac{24}{40}\\ =\frac{16+15+24}{40}\\ =\frac{55}{40}\\ =\frac{11}{8}\)