Question

найди значение выражения

Answer 1

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