Răspuns:
Explicație pas cu pas:
[tex](2x-7)^2 = 4x^2-28x+49\\(3x+4)^2 = 9x^2 + 24x + 16\\(5x-7)(5x+7) = 25x^2 + 35x-35x-49 = 25x^2-49\\(2x-y)^2 = 4x^2-4xy+y^2\\(5x-3y)^2 = 25x^2 - 30xy + 9y^2\\(6x-5y)(6x+5y) = 36x^2 + 30xy - 30xy - 25y^2 = 36x^2-25y^2\\\\(2x+1)^2 - 4x(x+1) = 4x^2+2x+1 - 4x^2 - 4x = -2x + 1\\(3x+2)^2 -3x(3x+4) = 9x^2 + 12x+4 - 9x^2 - 12x = 4\\(3x+4)^2 - (3x+2)(3x-2) = 9x^2 + 24x + 16 - 9x^2 + 4 = 24x + 20\\(2x+5)^2 - 4(x+2)(x-2) = 4x^2 + 20x + 25 -4x^2 + 16 = 20x + 41[/tex]