Question

Latihan soal mudah

Jika bc - 2b = 1
ab - a = 1
ac - 3c = 1

maka nilai abc = . . .

Answer 1

B(c - 2) = 1
a(b - 1) = 1
c(a - 3) = 1
_________ x
abc (abc - 2ab - ac + 2a - 3bc + 6b + 3c - 6) = 1
abc (abc - 2(1 + a) - (1 + 3c) + 2a - 3(1 + 2b) + 6b + 3c - 6) = 1
abc (abc - 2 - 2a - 1 - 3c + 2a - 3 - 6 - 6b + 6b + 3c - 6) = 1
abc (abc - 18) = 1
abc² - 18abc - 1 = 0
pakai rumus khawarizmi didapat
abc = 9 - √82 atau abc = 9 + √82