Thực hiện phép tính: 80/160 + 70/490 x 18/36

$\frac{80}{160}+\frac{70}{490}\times \frac{18}{36}$

$=\frac{1}{2}+\frac{1}{7}\times \frac{1}{2}$

$=\frac{1}{2}\times (1+\frac{1}{7})=\frac{1}{2}\times \frac{8}{7}=\frac{4}{7}$

80/160 + 70/490 x 18/36

= 1/2 + 1/7 x 1/2

= 1/2 x (1+1/7)

= 1/2 x 8/7

= 4/7

80/160 + 70/490 x 18/36

= 1/2 + 1/7 x 1/2

= 1/2 + 1/14

= 7/14 + 1/14

= 8/14 = 4/7