Jawapan

2015-09-04T20:00:14+08:00
(5x-3y)(5x-3y)
= 25x^2+15xy-15xy+9y^2
= 25x^2+9y^2
2015-09-05T00:25:36+08:00
= 25x² - 15xy - 15xy + 9y
= 25x² - 30xy + 9y²