The value of x which satisfies the equation
is
(a2 + b2 + c2)
- (a2 + b2 + c2)
(a2 + 2b2 + c2)
(a2 + 2b2 + c2)
If x4 + 2x3 + ax2 + bx + 9 is a perfect square, where a and b are positive real numbers, then the values of a and b are
a = 5, b = 6
a = 6, b = 7
a = 7, b = 6
a = 7, b = 6
If (a + b)2 = 100 and (a - b) = 4, then ab equals to
116
84
21
21
C.
21
(a + b)2 = 100
∴ a + b = 10 ...(i)
a - b = 4 ...(ii)
On solving equations (i) and (ii),
2a = 14 ⟹ a = 7, b = 3
∴ ab = 7 x 3 = 21