1) factorise les expressions :
A=3y+9 =3(y+3)
B=10x-7x²=x(10-7x)
C=(2t+9)(4t-7)-(t-8)(2t+9)
C=(2t+9)[(4t-7)-(t-8)]
C=(2t+9)(4t-7-t+8)
C=(2t+9)(3t+1)
D=(4x-2)²+x(4x-2)(x-1)
D=(4x-2)[(4x-2)+x(x-1)]
D=(4x-2)(4x-2+x²-x)
D=(4x-2)(x²+3x-2)
E=(3x-1)(5x-2)+(3x-1)(6x+7)
E=(3x-1)[(5x-2)+(6x+7)]
E=(3x-1)(5x-2+6x+7)
E=(3x-1)(11x+5)
....................................................
2)calcul les puissances:
-15 5 -15 -15 5 -15 -15 5 5 -15
3 × 15 × 5 3 × (3×5) × 5 3 × 3 × 5 × 5
E=...........................= ....................................= ............................................
40 40 40 40
15 (3×5) 3 × 5
-10 -10 -10 -10
3 × 5 3 5 -50 -50
E= ...........................= ......... × ......... = 3 × 5
40 40 40 40
3 × 5 3 5