The process is as follows: get from the meaning of the question

2ab+2a+2b*2=60

Ab=k(k is a constant)

After substituting into the equation, the equation about b or a is obtained. The quadratic equation has a solution if the discriminant is greater than 0, and the discriminant has a parameter k. According to this condition, k is 25, and then a=5b=5 is brought back to the equation.