![](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)
a) Bạn Nguyễn Lê Phước Thịnh giải rồi nha bạn :)
b) (-9-x+2)+9
=-9-x+2+9
=-9+(-x)+2+9
=(-x)+(-9+2+9)
=(-x)+2
c) 66-(12-x)+(12-66)
=66-12+x+12-66
=x
d) 15-(15-x+93)+93
=15-15+x-93+93
=x
![](https://rs.olm.vn/images/avt/0.png?1311)
a)x+(-81)-(11-81)
=x-81-11+81
=x-11
b)(-1-x+2)+1
=-1-x+2+1
=-x+2
c)15-(11-x)+(11-15)
=15-11+x+11-15
=x
d)15-(15-x+202)+202
=15-15+x-202+202
=x
![](https://rs.olm.vn/images/avt/0.png?1311)
a) \(x+\left(-81\right)-\left(11-81\right)=x-81-11+81=x-11\)
b) \(\left(-1-x+2\right)+1=\left(-1\right)-x+2+1=-x+2=2-x\)
c) \(15-\left(11-x\right)+\left(11-15\right)=15-11-x+11-15\)
\(=\left(15-15\right)+\left(11-11\right)+x=0+0+x=x\)
d) \(15-\left(15-x+202\right)=15-15+x-202=x-202\)
a)x-81-11+81=x-11
b)(-1-x+2)+1=-1-x+2+1=2-x
c)15-(11-x)+(11-15)=15-11+x+11-15=x
d)15-(15-x+202)+202=15-15+x-202+202=x
![](https://rs.olm.vn/images/avt/0.png?1311)
a, (-72).(15 - 49) + 15.(-56 + 72)
= -72 . 15 + 72.49 - 15.56 + 15.72
= (-72.15 + 15.72) + (72.49 - 15.56)
= 3528 - 84
= 2688
1b, 1532 + (-186) + (-1432) + (-14) + 123
= (1532 - 1432) - (186 + 14) + 123
= 100 - 200 + 123
= 223 - 200
= 23
\(\left(15-x\right)^2=81\)
\(\Rightarrow\left(15-x\right)^2=9^2\) hoặc \(\left(15-x\right)^2=\left(-9\right)^2\)
\(\Rightarrow15-x=9\) hoặc \(15-x=-9\)
\(\Rightarrow x=15-9\) hoặc \(x=15-\left(-9\right)=15+9\)
\(\Rightarrow x=6\) hoặc \(x=24\)
Vậy...
(15 - x)2 = 81
(15 - x)2 = 92
15-x = 9
x = 15 - 9
=> x = 6