bonjour
( 4 /3 - 1 + 1 /2) : ( - 5 /6 + 14/3 - 7 )
= ( 8/6 - 6 /6 + 3 /6) : ( - 5 /6 + 28/6 - 42/6)
= 5/6 : - 19/6
= 5/6 * - 6/19
= - 30 / 114
= - 5/19
16 x² - 4 x - ( 4 x - 1 ) ( 2 x + 1 )
4 x ( 4 x - 1 ) - ( 4 x - 1 ) ( 2 x + 1 )
( 4 x - 1 ) [ 4 x - 2 x - 1 )
( 4 x - 1 ) ( 2 x - 1 )