\[\boxed{\text{902\ (902).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ (x - 2y)(x + 2y) + 4y² =\]
\[= x^{2} + 2yx - 2yx - 4y^{2} + 4y^{2} =\]
\[= x²\]
\[\textbf{б)}\ (2a - 3b)(2a + 3b) - 3a^{2} =\]
\[= 4a^{2} - 9b^{2} - 3a^{2} = a^{2} - 9b²\]
\[\textbf{в)}\ (5x - 1)^{2} + 10x =\]
\[= 25x^{2} - 10x + 1 + 10x =\]
\[= 25x^{2} + 1\]
\[\textbf{г)}\ (3y + 4z)² - 8z(3y - 2z) =\]
\[= 9y^{2} + 32z²\]
\[= m^{3} - 2n^{3}\]
\[c^{6} + 64d³ - c^{6} + c^{2} = 64d^{3} + c^{2}\]
\[= x^{2} + 30y^{2}\]
\[= 8x^{3} + 24x^{2} + 18x - 8x^{3} + 27 =\]
\[= 24x^{2} + 18x + 27.\]