Question

Tìm x 

( 2^6 - 4x ) . 8^39 = 2 . 8^40 

Answer 1

( 2⁶ - 4x ) . 8³⁹ = 2 . 8⁴⁰

 2⁶ - 4x = 2 . 8⁴⁰ : 8³⁹

2⁶ - 4x = 2 . 8

      4x = 2⁶ - 16

      4x = 64 - 16

      4x = 48

       x = 48 : 4

       x = 12

Answer 2

( 2^6 - 4x ) . 8 ^39 = 2. 8 ^ 40

( 2 ^6 - 4x ) . 8 ^ 39 = 2 . 8 . 8 ^ 39

( 2 ^6 - 4x )             = 16

  64 - 4x                 = 16

        4x                  = 64 - 16

        4x                  =  48

          x                  =  48 : 4

          x                  = 12

Answer 3

\(\left(2^6-4x\right)\cdot8^{39}=2\cdot8^{40}\)

=>\(\left(2^6-4x\right)\cdot\left(\left(2\right)^3\right)^{39}=2\cdot\left(\left(2\right)^3\right)^{40}\)

=>\(\left(2^6-4x\right)\cdot2^{117}=2\cdot2^{120}\)

=>\(\left(2^6-4x\right)=2^{121}:2^{117}\)

=>\(\left(2^6-4x\right)=2^4\)

=>\(4x=2^6-2^4\)

=>\(4x=64-16\)

=>\(x=48:4\)

=>x=12

Answer 4

\(\left(2^6-4x\right).8^{39}=2.8^{40}\)

\(\Leftrightarrow\left(64-4x\right).\left(2^3\right)^{39}=2.\left(2^3\right)^{40}\)

\(\Leftrightarrow\left(64-4x\right).2^{117}=2.2^{120}=2^{121}\)

\(\Rightarrow\left(64-4x\right)=2^{121}\div2^{117}=2^4=16\)

\(\Leftrightarrow64-4x=16\)

\(\Leftrightarrow4x=64-16=48\)

\(\Leftrightarrow4x=48\)

\(\Leftrightarrow x=48\div4=12\)

Vay\(..........\)