Question

va rog ajutatima rezolvati
calcul prescurtat : (m-2n)la puterea a 2
descompuneti in factori a) (5a+7)la puterea a 2 - 4b la puterea a 2
b)25xla puterea a 2 - 9 =

Answer 1

[tex](m-2n)^2=m^2-4mn+4n^2;\\ a)\;(5a+7)^2-4b^2=(5a+7+2b)(5a+7-2b);\\ b)\;25x^2-9=(5x+3)(5x-3).[/tex]