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Exercise - 7 B

Solve the following quadratic equations :

Q. 1.

Q. 2.

Q. 3. x² - 6x + 2 = 0

Q. 4. x² + 8x + 4 = 0

Q. 5. 2x² + 5x - 3 = 0

Q. 6. -2x² + x + 1 = 0

Q. 7. x² + 2x - 8 = 0

Q. 8. 6x² + x - 2 = 0

Q. 9. 4x² + 12x + 9 = 0

Q. 10. (x + 4) (x + 5) = 3 (x + 1) (x + 2) + 2x

Q. 11.

Q. 12.

Q. 13.

Q. 14.

Q. 15.

Q. 16.

Q. 17.

Q. 18. Find the value of p for which the given equations has equal roots :

1. 4x² - 5x + p = 0
2. px² - 8x + 4 = 0
3. 9x² + 3px + 4 = 0
4. (p - 12) x² + 2 (p - 12) x + 2 = 0

Q. 19. Form a quadratic equation whose roots are :

1. 
2. 
3. 1, -8

Q. 20. Solve the equation 2x - 1/x = 7. Write your answer correct to two decimal places.

Answers
1.	2.	3.
4.	5. 1/2, -3	6. - (1/2)
7. 2, -4	8. 1/2, - (2/3)	9. - (3/2)
10.	11.	12. 4
13. 8, 20	14. 4/13, 9/13	15.
16. 1/2, 1, 2	17. 3/2, - (5/2)	18. (i) 25/6 (ii) 4 (iii) (iv) 14
19. (i) x2 - 4x - 1 = 0 (ii) x2 - 5x + 7 (iii) x2 + 7x - 8 = 0		20. 7.27, -0.27