a) \(70-5\left(x-3\right)=45\)
\(5\left(x-3\right)=25\)
\(x-3=5\)
\(\Rightarrow x=8\)
b) \(12+\left(5+x\right)=20\)
\(5+x=8\)
\(\Rightarrow x=3\)
c) \(130-\left(100+x\right)=25\)
\(100+x=105\)
\(\Rightarrow x=5\)
d) \(175+\left(30-x\right)=200\)
\(30-x=25\)
\(\Rightarrow x=5\)
e) \(5\left(x+12\right)+22=92\)
\(5\left(x+12\right)=70\)
\(x+12=14\)
\(\Rightarrow x=2\)
a. 70 - 5.(x - 3) = 45
5.(x - 3) = 70 - 45
x - 3 = 25 : 5
x = 5 + 3
x = 8
b. 12 + (5 + x) = 20
5 + x = 20 - 12
x = 8 - 5
x = 3
c. 130 - (100 + x) = 25
100 + x = 130 - 25
x = 105 - 100
x = 5
d. 175 + (30 - x) = 200
30 - x = 200 - 175
x = 30 - 25
x = 5
e. 5.(x + 12) + 22 = 92
5.(x + 12) = 92 - 22
x + 12 = 70 : 5
x = 14 - 12
x = 2
\(70-5\left(x+3\right)=45\) \(12+\left(5+x\right)=20\) \(130-\left(100+x\right)=25\)
\(5\left(x+3\right)=70-45\) \(5+x=20-12\) \(100+x=130-25\)
\(5\left(x+3\right)=25\) \(5+x=8\) \(100+x=105\)
\(x+3=25:5\) \(x=8-5\) \(x=105-100\)
\(x+3=5\) \(x=3\) \(x=5\)
\(x=5-3\)
\(x=2\)
\(175+\left(30-x\right)=200\) \(5\left(x+12\right)+22=92\)
\(30-x=200-175\) \(5\left(x+12\right)=92-22\)
\(30-x=25\) \(5\left(x+12\right)=70\)
\(x=30-25\) \(x+12=70:5\)
\(x=5\) \(x+12=14\)
\(x=14-12\)
\(x=2\)
Tìm x :
a. 70 - 5.(x - 3) = 45
5.(x - 3) = 70 - 45
x - 3 = 25 : 5
x = 5 + 3
x = 8
b. 12 + (5 + x) = 20
5 + x = 20 - 12
x = 8 - 5
x = 3
c. 130 - (100 + x) = 25
100 + x = 130 - 25
x = 105 - 100
x = 5
d. 175 + (30 - x) = 200
30 - x = 200 - 175
x = 30 - 25
x = 5
e. 5.(x + 12) + 22 = 92
5.(x + 12) = 92 - 22
x + 12 = 70 : 5
x = 14 - 12
x = 2
