Odpowiedź :
[tex]3x(5x - 7) = 15x^2 - 21x \\\\-7x(3r - 5) = -21rx + 35x\\\\5x(3 - 5r) = 15x - 25rx\\\\-3x(7 + 5x) = -21x - 15x^2[/tex]
[tex]3x(5x - 7) = 15x^2 - 21x \\\\-7x(3r - 5) = -21rx + 35x\\\\5x(3 - 5r) = 15x - 25rx\\\\-3x(7 + 5x) = -21x - 15x^2[/tex]