Question

88/x - 88/x+1=4/5
помогите пожалуйста ​

Answer 1

Ответ:

$\frac{88}{x} - \frac{88}{x + 1} = \frac{4}{5}$

$88(x + 1) - 88x = 0.8x(x + 1)$

$88x + 88 - 88x = 0.8 {x}^{2} + 0.8x$

$0.8 {x}^{2} + 0.8x - 88 = 0$

$d = {0.8}^{2} + 4 \times 88 \times 0.8 = 0.64 + 281.6 = 282.24 = {16.8}^{2}$

$x1 = \frac{ - 0.8 + 16.8}{2 \times 0.8} = \frac{16}{1.6} = 10$

$x2 = \frac{ - 0.8 - 16.8}{2 \times 0.8} = \frac{ - 17.6}{1.6} = - 11$

Ответ: х1=10, х2= -11