Given that log4(Y - 1) + log4(\(\frac{1}{2}\)x) = 1 and log2(y + 1) + log2x = 2, solve for x and y respectively
A
2, 3
B
3, 2
C
-2, -3
D
-3, -2
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
log4(y - 1) + log4(\(\frac{1}{2}\)x) = 1
log4(y - 1)(\(\frac{1}{2}\)x) \(\to\) (y - 1)(\(\frac{1}{2}\)x) = 4 ........(1)
log2(y + 1) + log2x = 2
log2(y + 1)x = 2 \(\to\) (y + 1)x = 22 = 4.....(ii)
From equation (ii) x = \(\frac{4}{y + 1}\)........(iii)
put equation (iii) in (i) = y (y - 1)[\(\frac{1}{2}(\frac{4}{y - 1}\))] = 4
= 2y - 2
= 4y + 4
2y = -6
y = -3
x = \(\frac{4}{-3 + 1}\)
= \(\frac{4}{-2}\)
X = 2
therefore x = -2, y = -3
Source: Myschool Past Questions Archive (Record #30619)