a. aX = 108, where a is the number of phonecards bought, and X is the price for one phonecard.
b. (a - 2) (X + 2) c. (a - 2) (X + 2) = 108 + 20 aX + 2a - 2X - 4 = 128 X = 108/a 108 + 2a - 216/a = 132 2a - 216/a = 24 a - 108/a - 12 = 0 a^2 - 12a - 108 = 0 a = 18 Wassalaam, -- Abu 'Abdirrahman, Ahmad Ridha bin Zainal Arifin bin Muhammad Hamim (l. 1400 H/1980 M) 2011/11/18 ZulTan <zul_...@yahoo.com> > > Ko matematika SMP: > > A shop keeper bought some phonecards $108. He paid $X for each. > > a. Find, in term of X, an expression for the number of phonecards he > bought. > > b. He gave away two number of phonecards to his son and sold remainder > for $2 per card more than he paid for it. Write down an expression in term > of X for the some money he received. > > c. He made $20 profit. Write down the equation and solve it to find the > number of phonecards he bought. > > Mungkin ado nan nio mancubo utak-atiak dipersilakan. > > Salam, > ZulTan, L, 51, Bogor > -- . * Posting yg berasal dari Palanta RantauNet, dipublikasikan di tempat lain wajib mencantumkan sumber: ~dari Palanta R@ntauNet http://groups.google.com/group/RantauNet/~ * Isi email, menjadi tanggung jawab pengirim email. =========================================================== UNTUK DIPERHATIKAN, melanggar akan dimoderasi: - DILARANG: 1. E-mail besar dari 200KB; 2. E-mail attachment, tawarkan di sini & kirim melalui jalur pribadi; 3. One Liner. - Anggota WAJIB mematuhi peraturan serta mengirim biodata! Lihat di: http://forum.rantaunet.org/showthread.php?tid=1 - Tulis Nama, Umur & Lokasi disetiap posting - Hapus footer & seluruh bagian tdk perlu dlm melakukan reply - Untuk topik/subjek baru buat email baru, tdk mereply email lama & mengganti subjeknya. =========================================================== Berhenti, bergabung kembali, mengubah konfigurasi/setting keanggotaan di: http://groups.google.com/group/RantauNet/
