Jawabanmu

2014-09-12T16:59:14+07:00
1. (m-n)² -1 = m² - n² -1
2. (a+b)² - (a-b)² = a² + 2ab + b² - (a²-2ab+b²) = a² + 4ab
3. 4(x-y)² - (x+y)² = 4(x²-2xy+y²)-(x²+2xy+y²) = 4x² - x² -8xy-2xy+4y²-y² = 3x²-10xy+3y²

1 5 1