ГДЗ по алгебре 7 класс Макарычев ФГОС Задание 831

\[\boxed{\text{831.}\text{\ }еуроки - ответы\ на\ пятёрку}\]

\[\textbf{а)}\ (12a - 1)^{2} - 1 = 144a^{2} -\]

\[- 24a + 1 - 1 = 144a^{2} - 24a\]

\[\textbf{б)}\ (2a + 6b)^{2} - 24ab = 4a^{2} +\]

\[+ 24ab + 36b^{2} - 24ab =\]

\[= 4a^{2} + 36b²\]

\[\textbf{в)}\ 121 - (11 - 9x)^{2} = 121 -\]

\[- \left( 121 - 198x + 81x^{2} \right) =\]

\[= 121 - 121 + 198x - 81x^{2} =\]

\[= - 81x^{2} + 198x\]

\[\textbf{г)}\ a²b² - (ab - 7)^{2} = a^{2}b^{2} -\]

\[- \left( a^{2}b^{2} - 14ab + 49 \right) =\]

\[= a^{2}b^{2} - a^{2}b^{2} + 14ab - 49 =\]

\[= 14ab - 49\]

\[\textbf{д)}\ b² + 49 - (b - 7)^{2} = b^{2} +\]

\[+ 49 - \left( b^{2} - 14b + 49 \right) =\]

\[= b^{2} + 49 - b^{2} + 14b - 49 =\]

\[= 14b\]

\[\textbf{е)}\ a^{4} - 81 - \left( a^{2} + 9 \right)^{2} = a^{4} -\]

\[- 81 - \left( a^{4} + 18a^{2} + 81 \right) =\]

\[= a^{4} - 81 - a^{4} - 18a^{2} - 81 =\]

\[= - 18a^{2} - 162\ \]