Answer :

Lilith
[tex]\frac{20}{40}-\frac{21}{40}\cdot \frac{80}{7}=\frac{\not20^1 }{\not40^2} - \frac{\not21^3}{\not40^1} \cdot \frac{ \not80^2}{\not7^1} = \frac{1}{2}- 6=-5\frac{1}{2}[/tex]


kate200468
[tex] \frac{20}{40} - \frac{21}{40} \cdot \frac{80}{7}= \frac{1}{2} - \frac{3\cdot7}{40}\cdot\frac{2\cdot40}{7}= \frac{1}{2} - \frac{3}{1}\cdot\frac{2}{1}= \frac{1}{2} -6=-5 \frac{1}{2}[/tex]

Other Questions