Question

1. What is the solution of log4(2x 6)=2?

5
7
11
14


2. What is the solution, or what are the solutions, of 2log6(x)=log6(100)?

10 only
-10 only
-10 and 10
no solution


3. What is the solution, or what are the solutions, of log9(x^2)=log9(25)?

5 only
-5 only
-5 and 5
no solution


4. What is the solution of log3(x + 7) + log3(3)=2?

-4
5
10
no solution

Answer 1

1.
log(4)( 2 x - 6 ) = 2
2 x - 6 = 4²
2 x - 6 = 16
2 x = 22
x = 11
Answer: C ) 11
2.
2 log(6) x = log(6)100
log(6)x² = log(6) 100
x² = 100, restriction x>0
Answer: A ) 10 only
3.
log(9) x² = log(9) 25
x² = 25
Answer: C ) - 5 and 5
4.
log(3) ( 3 x + 21 ) = 2
3 x + 21 = 3²
3 x + 21 = 9
3 x = -12
x = - 4
Answer: A ) - 4