Solving for time with an Overdamped Oscillator

[NewtonsHead]

Homework Statement

How long will it take until the mass is within 10% of its equilibrium?

I already solved most of what is needed in previous parts of the question. I just need help solving for t because it is in two exponents in the equation.

Homework Equations

This is the equation
x(t) = A₁*e^-(γ-q)*t + A₂*e^-(γ+q)*t
A₁ = 3.61
A₂ = -0.61
γ = 0.9
q = 0.64

The Attempt at a Solution

First I found where x is .1 from its equilibrium
x = .1A = .1(3m) = 0.3m
Then I plugged in the A values. I divided the right side of the equation by x and moved the whole A₂ term to the left of the equation to have an exponential on both sides.
Then I took the ln of both terms to have an equation with t on both sides.
-(γ+q)*(A₂/x )*t = -(γ-q)*(A₁/x)*t

If I plug these variables in, I am left with
number*t = number*t and that isn't really solvable...

 

[NewtonsHead]

Everytime I come up with an answer, it is negative but time can't be..