To solve the equation 1.2E-21 = (1.6E-19)(0.35967)ln(x/0.175), the first step involves isolating the natural logarithm term. This can be achieved by dividing both sides by (1.6E-19)(0.35967). After simplifying, the equation becomes ln(x/0.175) = (1.2E-21) / [(1.6E-19)(0.35967)]. Finally, exponentiating both sides will yield the value of x. Using a calculator or solver can help in finding the numerical solution efficiently.