a) x-12=-9+15
x-12=24
x=24+12
x=36
Vậy x=36
b)4x -12=400
4x=412
x=412:4
x=103
Vậy x=103
c)2x -35=15
2x=50
x=50:2
x=15
Vậy x=15
d)3x+17=2
3x=-15
x=(-15):3
x=-5
Vậy x=-5
e)\(\frac{-5}{8}=\frac{x}{16}\)
\(\Rightarrow\left(-5\right).16=8.x\)
\(\Rightarrow8x=-80\)
\(\Rightarrow x=-10\)
f)\(\frac{y}{10}=-\frac{4}{8}\)
\(\Rightarrow8y=\left(-4\right).10\)
\(\Rightarrow8y=-40\)
\(\Rightarrow y=-5\)
a) x - 12 = -9 + 15
=> x - 12 = 6
=> x = 6 + 12 = 18
b) 4x - 12 = 400
=> 4x = 400 + 12 = 412
=> x = 412 : 4 = 103
c) 2x - 35 = 15
=> 2x = 15 + 35 = 50
=> x = 50 : 2 = 25
d) 3x + 17 = 2
=> 3x = 2 - 17
=> 3x = -15
=> x = -15 : 3 = -5
e) \(\frac{-5}{8}=\frac{x}{16}\)
\(=>\frac{-10}{16}=\frac{x}{16}\)
=> x = -10
f) \(\frac{y}{10}=\frac{-4}{8}\)
\(=>\frac{y}{10}=\frac{-1}{2}\)
\(=>\frac{y}{10}=\frac{-5}{10}\)
=> y = -5
a) x - 12 = -9 + 15
x - 12 = 6
x = 12 + 6
x = 18
b) 4x - 12 = 400
4x = 412
x = 412 : 4
x = 103
c) 2x - 35 = 15
2x = 50
=> x = 25
d) 3x + 17 = 2
=> 3x = -15
=> x = -5
e) -5/8 = x/16
=> -10/16 = x/16
=> x = -10
y/10 = -4/8
=> y/10 = -40/80
=> y/10 = -5/10
=> y = -5
a) \(x-12=-9+15\Leftrightarrow x=-9+15+12=18\)
b) \(4x-12=400\Leftrightarrow4x=412\Leftrightarrow x=103\)
c) \(2x-35=15\Leftrightarrow2x=50\Leftrightarrow x=25\)
d) \(3x+17=2\Leftrightarrow3x=-15\Leftrightarrow x=-5\)
e) \(-\frac{5}{8}=\frac{x}{16}\Rightarrow x=\frac{-5\cdot16}{8}=-10\)
f) \(\frac{y}{10}=-\frac{4}{8}\Rightarrow x=\frac{10\cdot-4}{8}=-5\)
a) x - 12 = -9 +15
x - 12 = 6
x = 6+ 12
x = 18
b) 4x - 12 = 400
4x = 400+12
4x = 412
x = 412 : 4 =103
c) 2x - 35 = 15
2x = 15+35
2x = 50
x = 50: 2=25
d) 3x + 17=2
3x = 2 -17
3x = -15
x = -15 : 3= -5
e) -5 : 8 = x : 16
\(\frac{-5}{8}=\frac{x}{16}\)=> x = \(\frac{-5.16}{8}=\frac{-80}{8}=-10\)
f) y : 10 = -4 : 8
\(\frac{y}{10}=\frac{-4}{8}\)=> x =\(\frac{-4.10}{8}=\frac{-40}{8}=-5\)
a) x-12=-9+15
x = 6 + 12
x = 18
b)4x -12=400
4x = 400 + 12
4x = 412
x = 412 : 4
x = 103
c)2x -35=15
2x = 15 + 35
2x = 50
x = 50 : 2
x = 25
d)3x+17=2
3x = 2 - 17
3x = -15
x = -15 : 3
x = -5
e)-5/8=x/16
x = -5/8 . 16
x = -10
f)y/10=-4/8
y = -4/8 . 10
y = -5
\(a.\)
\(x-12=-9+15\)
\(\Rightarrow x-12=6\)
\(\Rightarrow x=6+12=18\)
Vậy : \(x=18\)
\(b.\)
\(4x-12=400\)
\(\Rightarrow4x=400+12=412\)
\(\Rightarrow x=412:4=103\)
Vậy : \(x=103\)
\(c.\)
\(2x-35=15\)
\(\Rightarrow2x=15+35=50\)
\(\Rightarrow x=50:2=25\)
Vậy : \(x=25\)
\(d.\)
\(3x+17=2\)
\(\Rightarrow3x=2-17=-15\)
\(\Rightarrow x=\left(-15\right):3=-5\)
Vậy : \(x=-5\)
\(e.\)
\(-\frac{5}{8}=\frac{x}{16}\)
\(\Rightarrow x=\frac{-5.16}{8}=-10\)
Vậy : \(x=-10\)
\(f.\)
\(\frac{y}{10}=-\frac{4}{8}\)
\(\Rightarrow y=\frac{-4.10}{8}=-5\)
Vậy : \(y=-5\)