Step 1 :

The verbal statement is " The rate of change of $\"\"$ with respect to $\"\"$ is proportional to $\"\"$ ".

Rate of change of $\"\"$ with respect to $\"\"$ : $\"\"$ .

$\"\"$

$\"\"$ .

The differential equation for the verbal statement is $\"\"$ , where $\"\"$ is a constant.

Step 2 :

The differential equation is $\"\"$ .

Integrate the above equation with respect to $\"\"$ .

$\"\"$

The solution of the differential equation is $\"\"$ .

Solution :

The differential equation is $\"\"$ .

The solution of the differential equation is $\"\"$ .