Question

помогите пожалуйста!!!!!!!!​

Answer 1

............................

Answer 2

$\frac{x {}^{2} - 49y {}^{2} }{7xy} \div ( \frac{1}{7y} + \frac{1}{x}) = \frac{x {}^{2} - 49y {}^{2} }{7xy} \div \frac{x+ 7y}{7xy} = \frac{x {}^{2} - 49y {}^{2} }{7xy} \times \frac{ 7xy}{x + 7y} = \frac{(x+7y)(x-7y)}{7xy} \times \frac{ 7xy}{x + 7y} = x - 7y$

Если х= 2 17/18, у=1 5/18, то

$2 \frac{17}{18} - 7 \times 1 \frac{5}{18} = \frac{53}{18} - 7 \times \frac{23}{18} = \frac{53}{18} - \frac{161}{18} = -6$