Question

Tìm x biết 

a,20 + 8.(x+3)=5^2.4

b,120+/x/=150

Answer 1

a. 20 + 8.(x + 3) = 5² . 4

8.(x + 3)             = 100 - 20

x + 3                  = 80 : 8

x                        = 10 - 3

x                        = 7

b. 120 + |x| = 150

|x|               = 150 - 120

|x|               = 30

x                 = + 30

Answer 2

a) 20 + 8(x + 3) = 5² . 4

 20 + 8(x + 3) = 100

8(X + 3) = 100 - 20

8(x + 3) = 80

x + 3 = 80 : 8

 x + 3 = 10

x = 10 - 3

x = 7

b) 120 + |x| = 150

|x| = 150 - 120

|x| = 30

=> \(\orbr{\begin{cases}x=30\\x=-30\end{cases}}\)

Answer 3

\(a,20+8.\left(x+3\right)=5^2.4\)

\(\Rightarrow20+8.\left(x+3\right)=25.4\)

\(\Rightarrow20+8.\left(x+3\right)=100\)

\(\Rightarrow8.\left(x+3\right)=100-20\)

\(\Rightarrow8.\left(x+3\right)=80\)

\(\Rightarrow x+3=80:8\)

\(\Rightarrow x+3=10\)

\(\Rightarrow x=10-3\)

\(\Rightarrow x=7\)

\(b,120+|x|=150\)

\(\Rightarrow|x|=150-120\)

\(\Rightarrow|x|=30\)

\(\Rightarrow x=\pm30\)

Answer 4

a) \(20+8\cdot\left(x+3\right)=5^2\cdot4\)

\(20+8\cdot\left(x+3\right)=100\)

\(8\cdot\left(x+3\right)=100-20=80\)

\(x+3=80:8=10\)

\(x=10-3=7\)

b) \(120+|x|=150\)

\(|x|=150-120=30\)

\(\Rightarrow x=\pm30\)

Answer 5

Tìm x biết : 

a) 20 + 8 . ( x + 3 ) = 5^2 . 4 

<=> 20 + 8 . ( x + 3 ) = 25 . 4 

<=> 20 + 8 . ( x + 3 ) = 100 

<=> 8 . ( x + 3 ) = 100 - 20

<=> 8 . ( x + 3 ) = 80 

<=> x + 3 = 80 : 8 

<=> x + 3 = 10 

<=> x = 10 - 3  

<=> x = 7 

Vậy x = 7 

b, 120 + | x |  = 150 

<=> | x | = 150 - 120 

<=> | x | = 30 

<=> x = 30 hoặc -30

Vậy x € { 30 ; -30 } 

Answer 6

a)20 + 8.(x+3)=5².4                                                        b)120+/x/=150

20 + 8.(x+3)=5.5.4                                                            /x/=150-120

20 + 8.(x+3)=5.20                                                             /x/=30

8.(x+3)=4.20                                                                     x = 30 hoặc x=-30

2(x+3)=20

x+3=10

x=17

Answer 7

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