Bonjour
1) Calculer :
A= 5/3×8/10÷(3-15/45)
A = 40/30 : [(3 x 3) / (1 x 3) - (15 x 1) / (15 x 3)]
A = 4/3 : (9/3 - 15/3)
A = 4/3 : (- 7/3)
A = 4/3 x - 3/7
A = - 12/21
A = (3 x - 4) / (3 x 7)
A = - 4/7.
2) Développer, réduire et ordonner :
f (x)= 2x(x-4)+(x+2)(2x-4)
f (x) = 2x² - 8x + 2x² - 4x + 4x - 8
f (x) = 2x² + 2x² - 8x - 8
f (x) = 4x² - 8x - 8
3) Factoriser :
f (x)=15x²-5x
f (x) = 5x (3x - 1)
g (n)= 8x²-24x
g (n) = 8x (x - 3)
