Your understanding of the first question is correct. Similar quadratic roots mean that the number of roots is the same after simplification. Remember to simplify.

For the second question, just calculate 3a-8= 17-2a. a=5。

The third problem is that the formula of a(a is greater than or equal to 0) under the root number is a quadratic root, so Party A under the root number is a quadratic root, and the root number 4 can be simplified to be equal to 2, so all others cannot guarantee that the number under the root number is greater than or equal to 0.

The fourth problem is to simplify x y on the numerator denominator of X and multiply it at the same time (root number 3- root number 2). Simplification equals 5-2. Similarly, the square root of 6 is multiplied by the numerator denominator of y (root number 3+ root number 2). The purpose is to remove the denominator and simplify it to the square root of 6 of 5+2. Then you can carry it in and do it yourself. You should be able to work it out