Răspuns :
1) a) 4a²-9
b) m² - 4mn + 4n²
2)( 3x+4)² = 9x² + 24x + 16
3) 25a²+ 70a + 49 - 4b²
1). a) (2a-3)(2a+3) = 4a² - 9 ;
b) (m-2n)² = m² - 4mn+4n² ;
2). ... (3x+ 4)² = 9x² + 24x +16 ;
3). ... (5x+7)² - 4b² =(5x+7-2b)(5x+7+2b)=(5x-2b+7)(5x+2b+7) ;
b) (m-2n)² = m² - 4mn+4n² ;
2). ... (3x+ 4)² = 9x² + 24x +16 ;
3). ... (5x+7)² - 4b² =(5x+7-2b)(5x+7+2b)=(5x-2b+7)(5x+2b+7) ;