bjr
ex 2
1er ligne :
a = -5
b = ?
c = 4
ab = 10 donc a x b = 10 comme a = -5 => b = -2 puisque -2 x (-5) = 10
(-a) x c = - (-5) x 4 = 5 x 4 = 20
- (ac) = - (-5 x 4) = - (-20) 20
abc = a x b x c = -5 x (-2) x 4 = 40
ligne 2
a = ?
b = ?
c = 2
-(ac) = - (a x c ) = -12 donc a x c = 12 => a = 6
tu finis ..
ex 1
A 8 cm B
6 cm
D C
1) aire rectangle = longueur x largeur - donc tu sais la calculer
2)
E =5/8AB F
= 1/3 de AD
H G
=> EF = 5/8 x AB = 5/8 x 8 = 5 cm
et EH = 1/3 x AD = 1/3 x 6 = 2 cm
tu peux calculer l'aire..
