Exercice 2 :
1) A = 6x + 24
= 6(x+4)
B = -42 + 7y
= 7(-6+y)
2) C = 7(3+x)
= 7*3 + 7*x
= 21 + 7x
D = -3(4-x)
= -3*4 + (-3) * (-x)
= -12 + 3x
Exercice 3 :
1) Par produit en croix, on a
400 m² → 50 kg
1500 m² → ? kg
[tex]\frac{50*1500}{400} = 187.5 kg[/tex]
2) 1 t = 1000 kg
50 kg → 400 m²
1000 kg → ? m²
[tex]\frac{400*1000}{50} = 8000[/tex] m²
3) Surface = 5*150 = 750 m²
400 m² → 50 kg
750 m² → ? kg
[tex]\frac{50*750}{400} = 93.75[/tex] kg
