Question

Помогите пожалуйста ​

Answer 1

1.

$( \frac{1}{b} + \frac{1}{4b} )\times \frac{b}{5} = ( \frac{4 + 1}{4b} ) \times \frac{b}{5} = \frac{5}{4b} \times \frac{b}{5} = \frac{5 \times b}{4b \times 5} = \frac{1 \times 1}{4 \times 1} = \frac{1}{4}$

2.

$(3 + \frac{1}{a} ) \div \frac{3a + 1}{a} = \frac{3a + 1}{a} \times \frac{a}{3a + 1} = \frac{(3a + 1)a}{a(3a + 1)} = 1$

3.

$( \frac{4}{x} + \frac{4}{x} )( \frac{1}{y} - \frac{1}{y} + \frac{x}{4} ) = \frac{8}{x} \times \frac{x}{4} = \frac{8x}{4x} = 2$