Question

1 . Tìm x thuộc N

2( x - 51 ) = 2.2² + 20

Answer 1

\(2\left(x-51\right)=2.2^2+20.\)

\(\Leftrightarrow2x-102=2.4+20\)

\(\Leftrightarrow2x-102=28\)

\(\Leftrightarrow2x=28+102\)

\(\Leftrightarrow2x=130\)

\(\Leftrightarrow x=130\div2\)

\(\Leftrightarrow x=65\)

Answer 2

2( x - 51 ) = 2.2² + 20

2( x - 51 ) = 2.4 +20

2( x - 51 ) = 28

    x - 51    = 28 : 2

     x - 51   = 14

           x    = 14 + 51

           x    =   65

Answer 3

2(x-51)=28

x-58=28:2=14

x = 14 + 58=72

Answer 4

2(x-51)=2³+20

2(x-51)=8+20

2(x-51)=28

x-51    =28:2

x-51    =14

x         =14+51

x         =65

Vậy x =65