Bonjour,
Factoriser:
- B(x)= (5x+10)(2x−5)−(x+3)²
B(x)= 10x²+20x-25x-50-x²-6x-9
B(x)= 9x²-11x-59
Δ= (-11)²-4(9)(-59)= 2245 > 0; 2 solutions
x1= (-(-1)-√2245)/2(9)= (11-√2245)/18
x2= (-(-1)+√2245)/2(9)= (11+√2245)/18
B(x)= (x- (11-√2245)/18))(x- (11+√2245)/18))
- R(x)=(7x−7)(2x−9)−(4−4x)(5x+1)
R(x)= 7(x-1)(2x-9)-4(1-x)(5x+1)
R(x)= 7(x-1)(2x-9) + 4(x-1)(5x+1) ***changement de signe
R(x)= (x-1)(7(2x-9+4(5x+1))
R(x)= (x-1)(14x-63+20x+4)
R(x)= (x-1)(34x-59)
