How Can You Solve the Equation 3^x + x = 4?

nineaxe · Apr 12, 2009

Homework Statement

3^x + x = 4

solve for x.

I'm thinking of using the logarithm laws. log(a.b) = log a + logb log(a/b) = log a - log b

log(a^b) = bloga

Well if I isolate the exponential
3^x = 4-x

take logs on both sides

xlog3 = log(4-x)

I can't seem to get the x out of the log.

Cyosis · Apr 12, 2009

You won't be able to find a solution algebraically. However the value for x is quite obvious. Take a good look at the equation in its original form.