Question

Составьте сюжетную : 42/17-х-40/17+х=1​

Answer 1

$\frac{42}{17 - x} - \frac{40}{17 + x} = 1 \\ \frac{42}{17 - x} - \frac{40}{17 + x} - 1 = 0 \\ \frac{42(17 + x) - 40(17 - x) - (17 - x) \times (17 + x)}{(17 - x)(17 + x)} = 0\\ \frac{714 + 42x - 680 + 40x - ( {17}^{2} - {x}^{2} )}{(17 - x)(17 + x)} = 0 \\ \frac{714 + 42x - 680 + 40x - {17}^{2} + {x}^{2} }{(1 7- x)(17 + x)} = 0 \\ \frac{34 + 82x - 289 + {x}^{2} }{(17 - x)(17 + x)} = 0 \\ - 255 + 82x + {x}^{2} = 0 \\ {x}^{2} + 82x - 255 = 0 \\ x = \frac{ - 82 \frac{ + }{ - } \sqrt{ {82}^{2} - 4 \times 1 \times ( - 255)} }{2 \times 1} \\ x = \frac{ - 82 \frac{ + }{ - } \sqrt{6724 + 1020} }{2} \\ x = \frac{ - 82 \frac{ + }{ - } \sqrt{7744} }{2} \\ x = \frac{ - 82 \frac{ + }{ - } 88}{2} \\ x = \frac{ - 82 - 88}{2} \\ x = \frac{ - 82 + 88}{2} \\ x = 3 \\ x = - 85 \\ x1 = - 85 \\ x2 = 3$