Решебник по математике 6 класс Виленкин ФГОС Часть 1, 2 Часть 2. П. 5. Решение уравнений Задание 99

\[\boxed{\text{5.\ 99}}\]

\[\textbf{а)} - 50 \cdot ( - 9x + 3) = - 15\ 000\]

\[- 9x + 3 = - 15\ 000\ :( - 50)\]

\[- 9x + 3 = 300\]

\[- 9x = 300 - 3\]

\[- 9x = 297\]

\[x = 297\ :( - 9)\]

\[x = - 33.\]

\[\textbf{б)}\ ( - 30x - 60) \cdot 2 = 120\]

\[- 30x - 60 = 120\ :2\]

\[- 30x - 60 = 60\]

\[- 30x = 60 + 60\]

\[- 30x = 120\]

\[x = 120\ :( - 30)\]

\[x = - 4.\]

\[\textbf{в)} - 4 \cdot (3 - 21x) = - 12\]

\[3 - 21x = - 12\ :( - 4)\]

\[3 - 21x = 3\]

\[- 21x = 3 - 3\]

\[- 21x = 0\]

\[x = 0.\]

\[\textbf{г)}\ 3,1 \cdot (15 - 5y) = - 93\]

\[15 - 5y = - 93\ :(3,1)\]

\[15 - 5y = - 30\]

\[- 5y = - 30 - 15\]

\[- 5y = - 45\]

\[y = 9.\]