If 2log3 y + log3 x2 = 4, then y is
A
4 - log3
B
\(\frac{4}{log_3 x}\)
C
\(\frac{4}{x}\)
D
\(\pm\) \(\frac{9}{x}\)
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
2log3y + log3x2 = 4
log3y2 + log3x2 = 4
∴ log3 (x2y2) = log381(correct all to base 4)
x2y2 = 81
∴ xy = \(\pm\)9
∴ y = \(\pm\)\(\frac{9}{x}\)
Source: Myschool Past Questions Archive (Record #31142)