Dani scribbled a memory-fragment: ( \frac{3^7}{3^4} ). “Subtract exponents,” she said. ( 3^{7-4} = 3^3 = 27 ).
Dani grinned. “So we’ll solve it like we solve equations — piece by piece.” matematika kelas 9 halaman 55
Rina and her best friend, Dani, sat on the floor of the school library, flipping through a worn-out math book. It was Matematika Kelas 9 , and they needed page 55 for their homework. Dani scribbled a memory-fragment: ( \frac{3^7}{3^4} )
Then they recalled a word problem: Sebuah amoeba membelah diri menjadi dua setiap 20 menit. Jika mula-mula ada 4 amoeba, berapa banyak setelah 2 jam? (“An amoeba splits into two every 20 minutes. Initially there are 4 amoeba, how many after 2 hours?”) how many after 2 hours?”)