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1014. The difference of two natural numbers is 3 and the difference of their3/28reciprocals is -. Find the numbers by quadratic equation |
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Answer» Answer: 7 and 4 Step-by-step EXPLANATION: Let the required numbers are 'x' and '3 - x' as their sum is x+(3-x) = 3. GIVEN, difference of their reciprocals is 3/28. ⇒ 1/(x - 3) - 1/x = 3/28 ⇒ (x - (x-3))/x(x - 3) = 3/28 ⇒ 3/x(x - 3) = 3/38 ⇒ 1/x(x - 3) = 1/28 ⇒ 28 = x(x - 3) ⇒ 0 = x² - 3x -28 Here, a = 1, b = -3, c = -28 Using quadratic formula, x = [-(-3) ± √(-3)² - 4(1)(-28) ]/2(1) = [3 ± √9 + 112 ] /2 = [3 ± √121]/2 = (3 + 11)/2 or (3 - 11)/2 = 7 or -4 Hence the required numbers are: if x = 7, x - 3 = 4 if x = -4, x -3 = -7 As the required numbers are natural, numbers are 7 and 4. |
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