determinan |5x..3x x..3| = 18. nilai x yang memenuhi

jawab

5x (3) - x(3x) = 18
15x - 3x² = 18
3x² - 15x + 18 = 0
3(x² - 5x +6) = 0
3(x  -3)(x - 2)= 0
x = 3 atau x = 2

det A = 18
5x(3) - 3x(x) = 18
15x - 3x² -18 = 0
3x² - 15x + 18 =0
————————— : 3
x² - 5x + 6 = 0
(x-2)(x-3) = 0
x = 2 V x= 3