Bonsoir,
Exercice 29
1)
carré = 2x*2x = 4x²
x=2
4x² = 4 * 2² = 4*4 = 16
rectangle: 8*x = 8x
8*2 = 16
2)
x= 3
4x² = 4*3*3 = 36
8x = 8*3 = 24
donc, non
Exercice 30
180 = 5x+2x+3x
180 = 10x
x = 180/ 10
x= 18
5x = 5*18 = >90°
2x = 2*18 =>36°
3x = 3*18 => 54°
