Posted by hurry! nick on Saturday, May 4, 2013 at 11:05am.
4 ^ ( x - 1 ) = 4 ^ x / 4 ^ 1 = 4 ^ x / 4
4 ^ x - 4 ^ ( x - 1 ) = 24
4 ^ x - 4 ^ x / 4 = 24
4 * 4 ^ x / 4 - 4 ^ x / 4 = 24
3 * 4 ^ x / 4 = 24 Multiply both sides by 4
3 * 4 ^ x = 96 Divide both sides by 3
4 ^ x = 32
x * log ( 4 ) = log ( 32 ) Divide both sides by log ( 4 )
x = log ( 32 ) / log ( 4 )
x = 3.465736 / 1.386294
x = 2.5
x = 5 / 2
log is " Natural logarithm " ( Logarithm with base e )