△=b？ -4ac This is the judgment formula in the book, which should be clearly written in the process of solving problems. In fact, your child must have thought of using this judgment formula when solving problems. Writing it on the test paper shows that you already know that this question is a judgment formula, and the calculation at the back shows that the candidate understands the judgment formula.

? The problem-solving process is the reflection of the examinee's problem-solving ideas. When you answer questions, you must get answers rigorously and reasonably.

? If mistakes are found, cross out the rewriting. But you must be able to read clearly the handwriting and the process of answering questions. This is not a composition, and untidy papers will not be deducted.