$\text{1) Đ}$
→ $\text{Vì}$ $2$ dm^{2}$ $30$$cm^{2}$ = $230$$cm^{2}$
$\text{2) S}$
→ $\text{Vì}$ $40$$dm^{2}$ $80$$cm^{2}$ = $4080$$cm^{2}$
$\text{3) S}$
→ $\text{Vì}$ $9$$dm^{2}$ $5$$cm^{2}$ = $905$$cm^{2}$
$\text{4) Đ}$
→ $\text{Vì}$ $205$$m^{2}$ $7$$dm^{2}$ = $20507$$dm^{2}$
$\text{5) Đ}$
→ $\text{Vì}$ $7$$dm^{2}$ $5$$cm^{2}$ = $705$$cm^{2}$
$\text{@mamthemmuoi}$