Put the equation in standard linear form.

Find the integrating factor.

Multiply both sides by
.

Now the left side the derivative of a product,

Integrate both sides.

On the right side, integrate by parts.

Solve for
.

You do 6/4, so the answer should be: 1.5 hours!
<em>Hope</em><em> </em><em>this</em><em> </em><em>will</em><em> </em><em>help</em><em> </em><em>u</em><em>.</em><em>.</em><em>.</em><em>:</em><em>)</em>