(5x+19) (5x-19) ajutoooooooooor

Răspuns :

se foloseste formula  => (a + b)(a - b) = a² - b² 

(5x+19) (5x-19) = (5x)² - 19² = 25x² - 361 
(5x+19)(5x-19)=(5x)²-19²=25x²-361