Quadratic Equations

5. The time taken by a person to cover $150$ km was $2.5 hrs$ more than the time taken in the return journey. If he returned at the speed of $10 km/hr$ more than the speed of going, what was the speed per hour in each direction?

Solution: Let the ongoing speed of person be x km/hr, Then, the returning speed of the person is $= (x + 10) km/hr$ (from the question) Using, speed = distance/ time Time taken by the person in...

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4. Find the values of k for which the following equations have real and equal roots (i) \[{{\mathbf{x}}^{\mathbf{2}}}~\text{ }\mathbf{2}\left( \mathbf{k}\text{ }+\text{ }\mathbf{1} \right)\mathbf{x}\text{ }+\text{ }{{\mathbf{k}}^{\mathbf{2}}}~=\text{ }\mathbf{0}\] (ii) \[{{\mathbf{k}}^{\mathbf{2}}}{{\mathbf{x}}^{\mathbf{2}}}~\text{ }\mathbf{2}\text{ }\left( \mathbf{2k}\text{ }\text{ }\mathbf{1} \right)\mathbf{x}\text{ }+\text{ }\mathbf{4}\text{ }=\text{ }\mathbf{0}\]

Solution: Given, \[{{\mathbf{x}}^{\mathbf{2}}}~\text{ }\mathbf{2}\left( \mathbf{k}\text{ }+\text{ }\mathbf{1} \right)\mathbf{x}\text{ }+\text{ }{{\mathbf{k}}^{\mathbf{2}}}~=\text{ }\mathbf{0}\] It’s...

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