a)12+x=-14
x=-14-12
x=-26
vậy x=-26
b)60-(5x-5)=45
5x-5=60-45
5x-5=15
5x=15:5
5x=3
x=\(\frac{3}{5}\)
vậy \(x=\frac{3}{5}\)
c)|15+3x|=32.5
|15+3x|=9.5
|15+3x|=45
* 15+3x=45 * 15+3x=-45
3x=45-15 3x=-45-15
3x=30 3x=-60
x=30:3 x=-60:3
x=10 x=-20
vậy x=10 hoặc x=-20
a, 12 + x = -14
=> x = -14 - 12
=> x = -26
b, 60 - ( 5x - 5 ) = 45
=> 5x - 5 = 60 - 45
=> 5x - 5 = 15
=> 5x = 20
=> x = 4
c, | 15 + 3x | = 32. 5
=> | 15 + 3x | = 45
\(\Rightarrow\orbr{\begin{cases}15+3x=45\\15+3x=-45\end{cases}\Leftrightarrow\orbr{\begin{cases}3x=30\\3x=-60\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=10\\x=-20\end{cases}}}\)
a, 12 + x = -14
x= -14-12
x= -26
b, 60-(5x-5) = 45
5x-5 = 60 -45
5x-5 = 15
5x = 15+5
5x = 20
x =20:5
x = 4
c, I15 + 3x I = 3^2 . 5
I15 +3xI = 9.5
I15+3xI = 45
TH1, 15+3x = 45
3x = 45 - 15
3x= 30
x= 30:3
x=10
TH2, 15+3x = -45
3x = -45-15
3x = - 60
x =-60 : 3
x= -20
Vậy ................................................................................................
hk tốt
a)12+x=-14
x=-14 - 12
x=-26
b)60 - (5x - 5) = 45
5x - 5 = 60 - 45
5x - 5 = 15
5x = 15 + 5
5x = 20
x=20 : 5
x = 4
c)|15 + 3x| = 32 . 5
|15 + 3x| = 9 . 5
|15 + 3x| = 45
Th1:
15 + 3x=45
3x = 45 - 15
3x = 30
x = 30 : 3
x = 10
Th2:
15 + 3x = -45
3x = -45 - 15
3x = -60
x = -60 : 3
x = -20
Học tốt!
b)60-(5x-5)=45
5x-5=60-45
5x-5=15
5x=15+5
5x=20
x=20:5
x=4
vậy x=4
Cảm ơn tất cả các bn nha:))
a)12+x=-14
=>x=(-14)-12
=>x=-26
b)60-(5x-5)=45
=>5x-5=60-45
=>5x-5=15
=>5x=15+5
=>5x=20
=>x=20:5
=>x=4
c)|15+3x|=3^2.5
=>|15+3x|=45
\(\Rightarrow\orbr{\begin{cases}15+3x=45\\15+3x=-45\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}3x=30\\3x=-60\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=10\\x=-20\end{cases}}\)
VẬY \(x\in\left\{10,-20\right\}\)
Đúng thì k nhé
a,12+x=-14\(\Rightarrow\)x=-14-12\(\Rightarrow\)x=-26
b,60-(5x-5)=45\(\Rightarrow\)5x-5=15\(\Rightarrow\)5x=20\(\Rightarrow\)x=4
c,|15+3x|=3^2*5\(\Rightarrow\)|15-3x|=45\(\Rightarrow\)15-3x=45\(\Rightarrow\)3x=-30\(\Rightarrow\)x=-10
15-3x=-45\(\Rightarrow\)3x=60\(\Rightarrow\)x=20
a) 12 + x = -14
x = -14 - 12
x = -26
b) 60 - (5x - 5) = 45
5x - 5 = 60 - 45
5x - 5 = 15
5x = 15 + 5
5x = 20
x = 20 : 5
x = 4
c) | 15 + 3x | = 32 . 5
| 15 + 3x | = 9 . 5
| 15 + 3x | = 45
\(\Rightarrow\orbr{\begin{cases}15+3x=45\\15+3x=-45\end{cases}}\Rightarrow\orbr{\begin{cases}3x=45-15=30\\3x=\left(-45\right)-15=60\end{cases}}\Rightarrow\orbr{\begin{cases}x=30\div3=10\\x=\left(-60\right)\div3=-20\end{cases}}\)
Bài giải
a, \(12+x=-14\)
\(x=-14-12\)
\(x=-26\)
b, \(60-\left(5x-5\right)=45\)
\(5x-5=60-45\)
\(5x-5=15\)
\(5x=15+5\)
\(5x=20\)
\(x=20\text{ : }5\)
\(x=4\)
c, \(\left|15+3x\right|=3^2\cdot5\)
\(\left|15+3x\right|=9\cdot5\)
\(\left|15+3x\right|=45\)
\(\Rightarrow\orbr{\begin{cases}15+3x=-45\\15+3x=45\end{cases}}\Rightarrow\orbr{\begin{cases}3x=-60\\3x=30\end{cases}}\Rightarrow\orbr{\begin{cases}x=-20\\x=10\end{cases}}\)
\(\Rightarrow\text{ }x\in\left\{-20\text{ ; }10\right\}\)