The answer on page 47-48 edited by Zhou Changyou, the second volume of Mathematics in Grade One, suggests that the questions should be posted one by one in the future, otherwise it is impossible to get the answer as you ask now.

People's education edition, the first volume of the first day, the world is connected with mathematics, with 70-73 pages of answers. Ask questions that you cannot ask. . . This is not good ~ ~

You should write your own answer homework on page 8 1 of the first volume of junior one mathematics. I am in Grade Two, and I know how to copy. What about the exam?

I minored in math, but I never copied my homework. I don't know how to ask the teacher, but I need to know how to learn. 、

Personal tutoring junior high school mathematics: the whole world knows the answer on pages 39~44. Then you might as well post the questions you don't know online and let us answer them for you. In that case, you can have a chance to exercise yourself. You can't depend on others for everything. It won't help you. If we help you, we will hurt you.

The answer on page 64 of the first volume of the Mathematics People's Education Edition "World Under Heaven" is that my brother is my sister's! Solution: ∫x? +2x-a+ 1=0 has no real root.

∴ Discriminant δδ< 0

b？ -4ac