Saved Bookmarks
| 1. |
The sum of two numbers is 15. Sum of its reciprocals is 3/10. Find the numbers. |
|
Answer» Let x, 15 – x be the numbers \(\frac{1}{x}+\frac{1}{15-x}=\frac{3}{10}\) \(\frac{15-x+x}{15x-x^2}=\frac{3}{10}\) 150 = 45x - 3x2 3x2 - 45x + 150 = 0 x2 - 15x + 50 = 0 \(x=\frac{-15\pm \sqrt{225-200}}{2}=\frac{15\,\pm\,5}{2}=10,5\) Numbers = 10, 5 |
|