2ha $7dam^{2}$ = ....... ha Gía trị biểu thức: 1$\frac{3}{5}$ + 2$\frac{1}{2}$ - 1$\frac{3}{10}$ A. 4$\frac{4}{5}$ B. 5$\frac{2}{5}$ C. 4$\frac{2}{5}$ D. 2$\frac{4}{5}$
2 câu trả lời
$\text{Câu 1 : Ta có : 2ha 7 dam² = 2ha + 0,07 ha = 2,07 ha }$
$\text{Vậy 2ha 7 dam² = 2,07 ha }$
$\text{Câu 2 : 1$\dfrac{3}{5}$ + 2$\dfrac{1}{2}$ - 1$\dfrac{3}{10}$ }$
$\text{= ( 2 + 1 - 1 ) + ( $\dfrac{3}{5}$ + $\dfrac{1}{2}$ - $\dfrac{3}{10}$ ) }$
$\text{= 2 + ( $\dfrac{6}{10}$ + $\dfrac{5}{10}$ - $\dfrac{3}{10}$ ) }$
$\text{= 2 + $\dfrac{8}{10}$ }$
$\text{= 2 + $\dfrac{4}{5}$ }$
$\text{= 2$\dfrac{4}{5}$ }$
$\text{⇒ D . 2$\dfrac{4}{5}$ }$