Question

Tìm x , biết

( 12x - 5 ) ( 4x -1 ) + ( 3x - 7 ) ( 1 - 16x ) = 81

Answer 1

( 12x - 5 ) ( 4x -1 ) + ( 3x - 7 ) ( 1 - 16x ) = 81

       48x²-12x-20x+5+3x-48x²-7+112x=81

       83x-2=81

       83x=83

       x=1

Vậy x=1

Answer 2

( 12x - 5 ) ( 4x -1 ) + ( 3x - 7 ) ( 1 - 16x ) = 81

48x² - 12x - 20x + 5 + 3x - 48x² - 7 + 112x = 81

83x = 81 - 5 + 7

83x = 83

x = 83/83

x = 1

Answer 3

PT<=> \(48x^2-32x+6-7-48x^2+115x=81\)

<=. 83x=82

<=> x=82/83