ГДЗ по алгебре 7 класс Мерзляк Задание 1002

\[\boxed{\text{1002\ (1002).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[1)\ (x - 8)^{2} - (x - 4)(x + 4) = 0\]

\[x^{2} - 16x + 64 - \left( x^{2} - 16 \right) = 0\]

\[x^{2} - 16x + 64 - x^{2} + 16 = 0\]

\[x^{2} - x^{2} - 16x = - 64 - 16\]

\[- 16x = - 80\]

\[x = 80\ :16\]

\[x = 5\]

\[Ответ:\ x = 5.\ \]

\[2)\ (4x - 5)(4x + 5) - (4x - 1)^{2} =\]

\[= 9 - 2x\]

\[16x^{2} - 25 - \left( 16x^{2} - 8x + 1 \right) =\]

\[= 9 - 2x\]

\[16x^{2} - 16x^{2} + 8x + 2x =\]

\[= 9 + 25 + 1\]

\[10x = 35\]

\[x = 35\ :10\]

\[x = 3,5\]

\[Ответ:\ x = 3,5.\ \]