Jawabanmu

2014-07-31T08:21:59+07:00
|A| = 3x.x - 5.2x
|A| =  3x^{2} - 10x

|B| = 3.5 - 2x.x
|B| = 15 - 2x^{2}

|A| = |B|
 3x^{2} - 10x = 15 - 2x^{2}
 3x^{2} + 2x^{2} - 10x - 15 = 0
 5x^{2} - 10x - 15 = 0 .......... bagi dengan 5
 x^{2} - 2x - 3 = 0
(x - 3) (x + 1) = 0
maka x = 3 atau x = -1