bantu pls

<h2>A. Permodelan Matematika</h2><p>x=buku, y=bolpoin</p><p>2x +3y = 19.000....(i)&nbsp;</p><p>3x + 2y = 21.000.....(ii)</p><h2>B. Menentukan harga per satuan</h2><p>(i) dikali 3, (ii) dikali 2, maka</p><p>6x + 9y = 57.000</p><p>6x + 4y = 42.000</p><p>(i)–(ii), maka</p><p>9y – 4y = 15.000</p><p>5y = 15.000</p><p>y = 3.000 → harga 1 bolpoin</p><p>subtitusikan y kedalam (i)&nbsp;</p><p>2x + 3(3000) = 19.000</p><p>2x = 10.000</p><p>x = 5.000 → harga 1 buku</p><h2>C. jika membeli 12 buku dan 10 bolpoin</h2><p>12x + 10y = 12(5000) + 10(3000) = 60.000 + 30.000</p><p>= 90.000</p><h2>D. kembaliannya</h2><p>uang Arya : 100.000</p><p>Kembaliannya: 100.000 – 90.000 = 10.000</p><p>&nbsp;</p><p>&nbsp;</p>