Quadratic Equation

5. in a flight of 600 Km, an aircraft was slowed down due to bad weather. Its average speed for trip was reduced by 200 Km/h and the time increased by 30 minutes. Find the duration of flight.
6. Zero are also called
7. and unknown term
9. Square root of a negative number
10. the expression b2−4ac is called the
12. term for non variable
14. polynomial, which has only one term
15. U-shaped plane curve

1. The sum S of first n natural numbers is given by S=n(n + 1)/n . Find n, if the sum is 351.
2. known as the "x" coordinate of a point, shown on the horizontal line,
3. is the second element in an ordered pair
4. A shopkeeper buys a number of books for Rs 80. If he had bought 4 more books for the same amount, each book would have cost him Re 1 less. How many books did he bought?
8. A polynomial with three unlike terms
11. a polynomial with only 2 terms
13. Find the value of k for which the roots of the quadratic equation (k -4)x2+2(k -4)x +2 = 0 are equal.