Given that P = x2 + 4x – 2, Q = 2x – 1 and Q – p = 2, find x
-
A.
-2 -
B.
-1 -
C.
1 -
D.
2
Correct Answer: Option B
Explanation
P = x2 + 4x – 2, Q = 2x – 1
Q – p = 2, (2x – 1) – (x2 + 4x – 2) = 2
2x – 1 – x2 – 4x + 2 = 2
-2x – x2 + 1
-x2 – 2x – 1 = 0
x2 + 2x + 1 = 0
x2 + x + x + 1 = 0
x(x + 1) + 1(x + 1) = 0
(x + 1)(x + 1) = 0
x + 1 = 0 or x + 1 = 0
x = -1 or x = -1
x = -1