- 6900" alt=" \frac{700}{x} - \frac{700}{x - 10} = 4 \\ 700(x - 10) - 700x = 4x(x - 10) \\ 700x - 7000 - 700x = {4x}^{2} - 40x \\ { - 4x}^{2} + 40x - 7000 = 0 \\ {x}^{2} - 10x + 1750 = 0 \\ d = { - 10}^{2} - 4 \times 1 \times 1750 = - 6900 \\ 0 > - 6900" align="absmiddle" class="latex-formula">
нет ответа.