![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
mai minh
học bài
này rùi bn
ráng đợi thêm
2 ngày nữa nhé
![](https://rs.olm.vn/images/avt/0.png?1311)
\(A=x+\left\{\left(x+5\right)-\left[\left(5-x\right)-\left(-x-3\right)\right]\right\}\)
\(=x+\left\{\left(x+5\right)-\left[5-x+x+3\right]\right\}\)
\(=x+\left\{\left(x+5\right)-\left(5+3\right)\right\}\)
\(=x+\left\{\left(x+5\right)-8\right\}\)
\(=x+\left\{x+5-8\right\}=x+\left\{x-3\right\}\)
\(=x+x-3=2x-3\)
\(B=x.\left\{\left[-x-2-\left[x+\left(3-x\right)-\left(x+3\right)\right]\right]\right\}\)
\(=x.\left\{\left[-x-2-\left[x+3x-x-x-3\right]\right]\right\}\)
\(=x\left\{\left[-x-2-\left(4x-2x-3\right)\right]\right\}\)
\(=x\left\{\left[-x-2-\left(2x-3\right)\right]\right\}\)
\(=x\left\{-x-2-2x+3\right\}\)
\(=x\left(1-3x\right)=x-3x^2\)
![](https://rs.olm.vn/images/avt/0.png?1311)
<=>x2+2x+1+3(x2+5x-5x-25)-(4x2-4x+1)
<=>x2+2x+1+3x2+15x-15x-75-4x2+4x-1
<=>6x=75
k mình nha bạn