a, \(15:\left(x+2\right)=3\Leftrightarrow x+2=3\Leftrightarrow x=1\)
b, \(20:\left(x+1\right)=2\Leftrightarrow x+1=10\Leftrightarrow x=9\)
c, \(240:\left(x-5\right)=2^2.5^2-20=80\Leftrightarrow x-5=3\Leftrightarrow x=8\)
d, \(96-3\left(x+1\right)=42\Leftrightarrow3\left(x+1\right)=54\Leftrightarrow x+1=18\Leftrightarrow x=17\)
a) 15 : (x + 2) = 3
x + 2 = 15 : 3
x + 2 = 5
x = 5 – 2 = 3
b) 20 : (1 + x) = 2
1 + x = 20 : 2
1 + x = 10
x = 10 – 1 = 9
c) 240 : (x – 5) = 22.52 – 20
240 : (x – 5) = 4.25 – 20
240 : (x - 5) = 100 – 20
240 : (x - 5) = 80
x – 5 = 240 : 80
x – 5 = 3
x = 3 + 5 = 8
d) 96 - 3(x + 1) = 42
3(x + 1) = 96 – 42
3(x + 1) = 54
x + 1 = 54 : 3
x + 1 = 18
x = 18 – 1
x = 17
\(15\div\left(x+2\right)=3\) \(20\div\left(1+x\right)=2\)
\(x+2=15\div3\) \(1+x=20\div2\)
\(x+2=5\) 1+x=10
x = 5 - 2 x=9
x = 3
\(240\div\left(x-5\right)=2^2\cdot5^2-20\) \(96-3\left(x+1\right)=42\)
\(240\div\left(x-5\right)=80\) \(3\left(x+1\right)=96-42\)
\(x-5=240\div80\) \(3\left(x+1\right)=54\)
x-5=3 \(x+1=54\div3\)
x=8 x+1=18
x=17
a) 15 : (x + 2) = 3
x + 2 = 15 : 3
x + 2 = 5
x = 5 - 2
x = 3
Vậy x = 3
b) 20 : (1 + x) = 2
1 + x = 20 : 2
1 + x = 10
x = 10 -1
x = 9
Vậy x = 9
c) 240 : (x – 5) = 22.52 – 20
240 : (x – 5) = 80
x – 5 = 240 : 80
x – 5 = 3
x = 3 + 5
x = 8
Vậy x = 8
d) 96 - 3(x + 1) = 42
- 3(x + 1) = 96 - 42
- 3(x + 1) = 54
x + 1 = 54 : (-3)
x + 1 = -18
x = -18 - 1
x = -19
Vậy x = -19
a) \(15:\left(x+2\right)=3\)
\(\Rightarrow x+2=15:3=5\\ \Rightarrow x=5-2=3\)
b)\(20:\left(1+x\right)=2\\ \Rightarrow1+x=20:2=10\\ \Rightarrow x=10-1=9\)
c)\(\text{240 : (x – 5) = 2^2 * 5^2 – 20 }\\\text{240 : (x – 5) = 80 }\\ \Rightarrow x-5=240:80=3\\ \Rightarrow x=3+5=8 \)
d)\(\text{ 96 - 3(x + 1) = 42}\\ \Rightarrow3\left(x+1\right)=96-42=54\\ \Rightarrow x+1=54:3=18\\ \Rightarrow x=18-1=17\)
