Page 42 - CHAPTER 4 (Quadratic equations)

CHAPTER 4

QUADRATIC EQUATIONS

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16. The value of k, so that the 2x +kx-5=0 and x -3x- 4 =0 have one in
common is

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(A) -2,-3 (B) -3, −
4
(C) -5,-6 (D) None of these

2
17. If the expression x -11x + a and x -14x+2 must have a common factor
2
and a≠0 , then the common factor is

(A) (x-3) (B) (x-6)

(C)(x-8) (D) None of these

18. The value of m for which one Of the roots of x -3x+2m=0 is double
2
of one of the roots of x -x+ m=0 is double of one of the roots of x
2
2
-x + m=0 is

(A) 0,2 (B) 0,-2

(C) 2,-2 (D) None of these

19. If the equations x + bx + c=0 and x + cx +b=0, (b≠ c) have a
2
2
common root. Then

(A)b+c=0 (B) b+c=1

(C) b+c+1=0 (D) None of these

2
20. If both the roots of the equations k(6x + 3) + rx + 2x -1=0 and 6k (2x
2
2
+ 1) + px + 4x -2=0 are common, then 2r-p is equal to
2
(A)1 (B) 2

(C)4 (D) 5

21. If x -ax-21=0 and x -3ax + 35=0 , a > 0 have a common root. then a is
2
2
equal to

(A)1 (B)2 (C)4 (D)5

2
22. The values of a for which the quadratic equation (1-2a) x -6ax-1=0

2
and ax -x+1=0 have at least one root in common are:
1
2
1
1
2
3
2
(A) , (B)0, (C) , - (D)0, ,
2 9 2 9 4 2 9

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