Question

найди значение выражения

Answer 1

$\frac{y {}^{2} - 6y + 9 }{y {}^{2} - 9 } \div \frac{10y - 30}{y {}^{2} + 3y } = \frac{(y - 3) { {}^{2} } }{(y - 3)(y + 3)} \div \frac{10(y - 3)}{y(y + 3)} = \frac{y - 3}{y + 3} \times \frac{y(y + 3)}{10(y - 3)} = \frac{y}{10} = \frac{70}{10} = 7$