Question

Solving Exponential Equations (lacking a common base)
4^x-5=8

Answer 1

6.5

Explanation:

4^(x-5) = 8

2^[2(x-5)] = 2³

Equating powers:

2(x-5) = 3

x-5 = 3/2

x = 13/2 or 6½

Answer 2

x= 6 1/2 or 6.5

Explanation:

4^x-5 =8

2^2(x-5) =2^3

since the base is equal, the powers are equal

2(x-5) = 3

2x - 10 = 3

2x = 3 + 10

2x = 13

2x/2 = 13/2

x = 6 1/2 or 6.5