Question

Solve, round to four decimal places if necessary:

log4(x-9)=2

Answer:
x-9=4^2
x-9=16
x=11


log4(z)+log4(z-3)=1
Answer:
z+z-3=1
2z=4
z=2

Thanks for checking my work.

Answer 1

Answer:
x-9=4^2
x-9=16
x=11 BUT 16 PLUS 9 = 25

log A + log B = log (A+B) !!!!
log4 (z^2 - 3 z ) = 1
z^2 - 3 z = 4^1 = 4
z^2 -3 z -4 = 0
(z-4)(z+1) = 0
z = 4 or -1

Answer 2

log A + log B = log (A*B) !!!!