Bonjour,
(4x -1)² : IR
(a-b)² = a² -2ab +b²
(4x -1)² - (16x² +2-4x +8)
= 16x² -8x +1 - 16x² - 2 +4x-8
= 4x -9
Développer:
(4x-1)(4x-1)- (16x²+2-4x+8)= 16x²-4x-4x+1-(16x²-4x+10)
= 16x²-8x+1-16x²+4x-10= -4x-9
