`1.` Hers

`2.` Your; mine

`3.` Theirs; ours

`4.` His

`5.` Mine

`6.` His

`7.` Mine; yours

`8.` My; your

`9.` Its

`10.` Its; its

`@Nae`

`Answer`

`78.` Choose `B`

`79.` Choose `A`

`80.` Choose `D`

`@Nae`

Đặt `A=1.2+2.3+...+18.19`

`3A=1.2(3-0)+2.3(4-1)+...+18.19(20-17)`

`3A=1.2.3-0.1.2+2.3.4-1.2.3+...+18.19.20-17.18.19`

`3A=18.19.20=6840`

\(\Rightarrow\) `A=6840/3`

\(\Rightarrow\) `A=2280`

`@Nae`

`a)5dm^3` `15cm^3>515cm^3`

`7dm^3` `7cm^3=7007cm^3`

`9dm^3` `456cm^3<9500cm^3`

`b)3m^3` `750dm^3=3,75m^3`

`4754dm^3<4,8m^3`

`6m^3` `2dm^3=6,2m^3`

`@Nae`

\(\dfrac{-2}{9}\). \(\dfrac{3}{4}\) \(+ \) \(\dfrac{3}{4}\) . \(\dfrac{-7}{9}\) \(+\) \(2\)\(\dfrac{1}{3}\)

\(=\) \(\dfrac{3}{4}\) . `(-2/9-7/9)+7/3`

`=3/4` . `(-1)+7/2`

`=19/12`

`@Nae`

Lan/be/intelligent/student/of all.

\(\Rightarrow\) Lan is the most intelligent student of all.

`@Nae`

(-2)/5 x 4/7 + (-3)/5 x 2/7 + (-3)/5

`=(-8)/3 +(-6)/35+(-3)/5`

`=(-8)-6-21/35`

`=(-35)/35`

`=(-1)`

`@Nae`

`(-2)/5.4/7+(-3)/5.2/7+(-3)/5`

`=(-8)/3 +(-6)/35+(-3)/5`

`=(-8)-6-21/35`

`=(-35)/35`

`=(-1)`

`@Nae`

Dzaa, kcj nhé bạn

`Answer`

How much

`@Nae`