Find x, such that 4^_7x=16.

Since 4^2=16, _7x must equal 2. Writing the equation _7x=2 in exponential form gives 7^2=x, so x=49.

jmc

algebra intermediate

Problem

Find

x

, such that

4^{l o g_{7} x} = 16

Solution

Since

4^{2} = 16

lo g_{7} x

must equal

2

. Writing the equation

lo g_{7} x = 2

in exponential form gives

7^{2} = x

, so

x = 49

Final answer