Question

помогите пожалуйста ​

Answer 1

Ответ:

$1) \frac{ {y}^{2} - 40y + 8}{4 { {y}^{2} }} \\ 2) \frac{2d}{25 - {d}^{2} } \\ 3) \frac{14a - 3}{a(a + 5)}$

Объяснение:

$1) \: \: \frac{y - 20}{4y} - \frac{5y - 2}{ {y}^{2} } = \frac{y(y - 20)}{4 {y}^{2} } - \frac{4(5y - 2)}{4 {y}^{2} } = \frac{y(y - 20) - 4(5y - 2)}{4 {y}^{2} } = \frac{ {y}^{2} - 20y - 20y + 8}{4 {y}^{2} } = \frac{ {y}^{2} - 40y + 8}{4 {y}^{2} }$

$2) \: \: \frac{1}{5c - d} - \frac{1}{5c +d } = \frac{(5c + d)}{(5c - d)(5c + d)} - \frac{(5c - d)}{(5c + d)(5c - d)} = \frac{(5c + d) - (5c - d)}{25с² - {d}^{2} } = \frac{5c + d - 5c + d}{25с² - {d}^{2} } = \frac{2d}{25с² - {d}^{2} }$

$3) \: \: \frac{7}{ a+ 5} + \frac{7a - 3}{ {a}^{2} + 5a } = \frac{7}{ a+ 5} + \frac{7a - 3}{a(a + 5)} = \frac{7a}{a( a+ 5)} + \frac{7a - 3}{a(a + 5)} = \frac{7a + 7a - 3}{a(a + 5)} = \frac{14a - 3}{a(a + 5)}$