Question

Найдите значение выражения:

1) 6/(5x-20) - (X-5)/(X^2-8X+16), Если X = 5

Answer 1

$\frac{6}{5x - 20} - \frac{x - 5}{ {x}^{2} - 8x + 16 } = \frac{6}{5(x - 4)} - \frac{x - 5}{ {(x - 4)}^{2} } = \frac{6(x - 4) - 5(x - 5)}{ 5{(x - 4)}^{2} } = \frac{6x - 24 - 5x + 25}{5( {x - 4)}^{2} } = \frac{x + 1}{5{(x - 4)}^{2} }$

$x = 5$

$\frac{5 + 1}{5( {5 - 4)}^{2} } = \frac{6}{5 \times {1}^{2} } = \frac{6}{5 \times 1} = \frac{6}{5} = 1.2$

Answer 2

Объяснение:

6/(5x -20) - (х - 5)/(х² - 8х + 16) =

6/5(х - 4) - (х - 5)/(х - 4)² =

6(х - 4) - 5(х - 5) / 5(х - 4)² =

6х - 24 - 5х + 25 / 5(х - 4)² =

х + 1 / 5(х - 4)²

х = 5

х + 1 / 5(х - 4)² = 5 + 1 / 5(5 - 4)² = 6/5 * 1² =

6/5 * 1 = 6/5 = 1 1/5 или 1,2