1. 900 cm^2 + 4 m^2 + 6 dam^2 = . . . dm^2 2. 6 hm^2 + 4

1. $60409 \text{ dm}^2$; 2. $604,78 \text{ a}$

Pembahasan

Untuk menyelesaikan soal konversi satuan luas ini, kita perlu mengubah semua satuan ke desimeter persegi (dm²) dan are (a).

1. $900 \text{ cm}^2 + 4 \text{ m}^2 + 6 \text{ dam}^2 = ... \text{ dm}^2$
   - $1 \text{ cm} = 0,1 \text{ dm}$, maka $1 \text{ cm}^2 = (0,1)^2 \text{ dm}^2 = 0,01 \text{ dm}^2$. Jadi, $900 \text{ cm}^2 = 900 \times 0,01 \text{ dm}^2 = 9 \text{ dm}^2$.
   - $1 \text{ m} = 10 \text{ dm}$, maka $1 \text{ m}^2 = 10^2 \text{ dm}^2 = 100 \text{ dm}^2$. Jadi, $4 \text{ m}^2 = 4 \times 100 \text{ dm}^2 = 400 \text{ dm}^2$.
   - $1 \text{ dam} = 10 \text{ m} = 100 \text{ dm}$, maka $1 \text{ dam}^2 = 100^2 \text{ dm}^2 = 10000 \text{ dm}^2$. Jadi, $6 \text{ dam}^2 = 6 \times 10000 \text{ dm}^2 = 60000 \text{ dm}^2$.
   - Jumlahkan semua hasil konversi: $9 \text{ dm}^2 + 400 \text{ dm}^2 + 60000 \text{ dm}^2 = 60409 \text{ dm}^2$.

2. $6 \text{ hm}^2 + 4 \text{ dam}^2 + 78 \text{ m}^2 = ... \text{ a}$
   - $1 \text{ hm} = 100 \text{ m}$, maka $1 \text{ hm}^2 = 100^2 \text{ m}^2 = 10000 \text{ m}^2$. Karena $1 \text{ a} = 100 \text{ m}^2$, maka $1 \text{ hm}^2 = 100 \text{ a}$. Jadi, $6 \text{ hm}^2 = 6 \times 100 \text{ a} = 600 \text{ a}$.
   - $1 \text{ dam} = 10 \text{ m}$, maka $1 \text{ dam}^2 = 10^2 \text{ m}^2 = 100 \text{ m}^2$. Karena $1 \text{ a} = 100 \text{ m}^2$, maka $1 \text{ dam}^2 = 1 \text{ a}$. Jadi, $4 \text{ dam}^2 = 4 \times 1 \text{ a} = 4 \text{ a}$.
   - $1 \text{ a} = 100 \text{ m}^2$. Jadi, $78 \text{ m}^2 = \frac{78}{100} \text{ a} = 0,78 \text{ a}$.
   - Jumlahkan semua hasil konversi: $600 \text{ a} + 4 \text{ a} + 0,78 \text{ a} = 604,78 \text{ a}$.

Jadi, jawabannya adalah: 1. $60409 \text{ dm}^2$; 2. $604,78 \text{ a}$.