Jawabanmu

2014-08-28T19:22:17+07:00
(2x + 5).(5x +9)
=2x.5x + 2x.9 + 5.5x + 5.9
=10x2 + 18x + 25x + 45
=10x2 + 43x + 45

10x2 =maksudnya x kuadrat / x pangkat 2
2014-08-28T19:22:58+07:00
(2x + 5) . (5x + 9) = 2x . 5x + 5 . 9
                           = 10x + 45
2 3 2