Question

Tìm x,biết

a, 3 : ( 1 - 3/2x ) = 4 : ( 2 - x )

b, 2.3^x + 3^x-1 = 7( 3² + 2.6² )

  giúp mk nha các bn ai nhanh mk sẽ k

Answer 1

a, 3 : ( 1 - 3/2x ) = 4 : ( 2 - x )

<=> \(\frac{3}{1-\frac{3}{2}x}=\frac{4}{2-x}\)

<=> 3 ( 2 - x ) = 4 ( 1 - 3/2x )

<=> 6 - 3x = 4 - 6x

<=> -3x + 6x = 4 - 6

<=> 3x = -2

<=> x = -2/3

b, 2.3^x + 3^x-1 = 7( 3² + 2.6² )

Answer 2

b, 2.3^x + 3^x-1 = 7( 3² + 2.6² )

<=> 2.3^x + 3^x-1 = 7.81

<=> 3^x-1(2.3 + 1) = 7.81

<=> 3^x-1.7 = 7.81

<=> 3^x-1=81

<=> 3^x-1 = 3⁴

=> x - 1 = 4 => x = 5

Answer 3

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