Докажите тождество:
1) $4a^2 - (6a^2 - 2ab) + (3ab + 2a^2) = 5ab$;
2) $(9x^6 - 4x^3) - (x^3 - 9) - (8x^6 - 5x^3) = x^6 + 9$.
$4a^2 - (6a^2 - 2ab) + (3ab + 2a^2) = 5ab$
$4a^2 - (6a^2 - 2ab) + (3ab + 2a^2) = 4a^2 - 6a^2 + 2ab + 3ab + 2a^2 = (4a^2 - 6a^2 + 2a^2) + (2ab + 3ab) = 0 + 5ab = 5ab$
$(9x^6 - 4x^3) - (x^3 - 9) - (8x^6 - 5x^3) = x^6 + 9$
$(9x^6 - 4x^3) - (x^3 - 9) - (8x^6 - 5x^3) = 9x^6 - 4x^3 - x^3 + 9 - 8x^6 + 5x^3 = (9x^6 - 8x^6) + (-4x^3 - x^3 + 5x^3) + 9 = x^6 + 0 + 9 = x^6 + 9$
Пожауйста, оцените решение
