A. -21
B. 1
C. 61
D. 21
Explanation:
a2 + b2 + ab = a2 + b2 + 2ab – ab
i.e., (a + b)2 – ab
from x2 – 9x + 20 = 0, we have
a + b = 9 and ab = 20. Hence the value of required expression (9)2 – 20 = 61.
A. -21
B. 1
C. 61
D. 21
Explanation:
a2 + b2 + ab = a2 + b2 + 2ab – ab
i.e., (a + b)2 – ab
from x2 – 9x + 20 = 0, we have
a + b = 9 and ab = 20. Hence the value of required expression (9)2 – 20 = 61.
A. x2 + 13x – 140 = 0
B. x2 – 13x + 140 = 0
C. x2 – 13x – 140 = 0
D. x2 + 13x + 140 = 0
A. 3
B. 4
C. 5
D. 6
A. 15
B. 14
C. 24
D. 26
A. 3x2 + 5x – 2 = 0
B. 3x2 + 5x + 2 = 0
C. 3x2 – 5x + 2 = 0
D. 3x2 – 5x – 2 = 0
A. -5, 3
B. 3, 5
C. -3, 5
D. -3, -5
A. rational and unequal
B. complex
C. real and equal
D. irrational and unequal
A. 10, 3
B. -10, 3
C. -20, 3
D. -10, -3
A. -2, -1/2
B. 4, -1
C. 4, 1
D. -2, 5/2
A. -6, 7
B. -8, 7
C. 14, -3
D. -7, 6
A. -6, 3
B. 3, -2/3
C. -5, 2
D. -9, 2
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