a, ( 19.x + 2.52 ) : 14 = ( 13 - 8 )2
=> ( 19.x + 6,25 ) : 14 = 25
=> ( 19.x + 6,25 ) = 25 . 14
=> ( 19.x + 6,25 ) = 350
=> 19.x = 350 - 6,25
=> 19.x = 343,75
=> x = 343,75 : 19
=> x = ?
a) (19x + 50) : 14 = 9 nên x=4
b) 2.3x = 10.312 + 8.312
2.3x = 312 (10 + 8) ; 2.3x = 312.18
3x = 312.32 ; 3x = 314 . Vậy x = 14