Tìm thỏa mãn:
Trả lời:
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)
Ta có : -12(x-5) + 7(3-x) = 5
=> (-12)x + 60 +21 - 7x =5
=> x (-12 -7) = 5-60-21
=> (-19)x = -76
=> x = (-76) : (-19)
=> x = 4
Vậy x = 4
![](https://rs.olm.vn/images/avt/0.png?1311)
2 . |x + 9| = 10
=> 2 . (x + 9) = 10 hoặc 2 . (x + 9) = -10
=> x + 9 = 10 : 2 hoặc x + 9 = -10 : 2
=> x + 9 = 5 hoặc x + 9 = -5
=> x = 5 - 9 hoặc x = -5 - 9
=> x = -4 hoặc x = -14
Mà x lớn nhất.
=> x = -4
![](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)
3600 : [ ( 5x + 335 ) : x ] = 50
<=> (5x + 335 ) : x = 3600 : 50 =72
<=> 5x + 335 = 72x
<=> 335 = 72x - 5x
<=> 335 = 67x
<=> x = 335 : 67 = 5
3600 : [ ( 5x + 335 ) : x ] = 50
<=> ( 5x + 335 ) : x = 3600 : 50 = 72
<=> 5x + 335 = 72x
<=> 335 = 72x - 5x
<=> 335 = 67x
<=> x = 335 : 67 = 5
![](https://rs.olm.vn/images/avt/0.png?1311)
-12(x-5)+7(3-x)=5
=>(-12x)-(-60)+21-7x=5
=>(-12x-7x)=5-(60+21)=5-84=-76
=>(-19x)=-76=>x=4
Vậy x=4
- 12.( x - 5 ) + 7.( 3 - x ) = 5
=> - 12x + 60 + 21 - 7x = 5
=> ( - 12x - 7x ) + 60 + 21 = 5
=> - 19x + 81 = 5
=> - 19x = 5 - 81
=> - 19x = - 76
=> x = ( - 76 ) : ( - 19 )
=> x = 4
Vậy x = 4
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Ta có: -210=(-1)+(-2)+(-3)+...+(-x+1)+(-x)
-210=-[1+2+3+...+(x-1)+x)]
-210=\(-\left[\frac{x\left(x+1\right)}{2}\right]\)
hay 210=\(\left[\frac{x\left(x+1\right)}{2}\right]\)
=> x(x+1)=210.2=420
=> 20.21=420 => x=20
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(-12\left(x-5\right)+7\left(3-x\right)=5\)
\(-12x+60+21-7x=5\)
\(-19x+81=5\)
\(-19x=81-5=76\)
\(x=\frac{76}{-19}=-4\)
\(\Rightarrow x=-4\)