Question

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504 : ( 16 - 3 . x ) = 72

( 2² . x - 5² ) . 3⁸ = 3⁹

Answer 1

\(\Rightarrow16-3x=504:72=7\\ \Rightarrow3x=16-7=9\Rightarrow x=3\\ \left(2^2\cdot x-5^2\right)\cdot3^8=3^9\\ \Rightarrow4x-25=3^9:3^8=3\\ \Rightarrow4x=28\Rightarrow x=7\)

Answer 2

504 : (16 - 3x) = 72 (ĐK: \(x\ne\dfrac{16}{3}\))

<=> 16 - 3x = 504 : 72

<=> 16 - 3x = 7

<=> 16 - 7 = 3x

<=> 3x = 9

<=> x = 3 (tM)

(2²x - 5²) . 3⁸ = 3⁹

<=> (4x - 25) . 6561 = 19683

<=> 4x - 25 = 19683 : 6561

<=> 4x - 25 = 3

<=> 4x = 3 + 25

<=> 4x = 28

<=> x = 7