Jawabanmu

2014-08-29T19:06:34+07:00
Gunakan perkalian pelangi,
a.) 10x(2y-10) = 20xy - 100x
b.) (x+5)x(5x-1) = (x+5)(5x-1) = 5x² - x + 25x - 5 = 5x² + 24x - 5
c.) (7-2x)x(2x-7) = (7-2x)(2x-7) = 14x - 49 - 4x² + 14x = -4x² + 28x - 49

Semoga membantu
20 4 20
2014-08-29T21:26:14+07:00