1) aire EBHI = EB² = 6² = 36
2)a) AB=AD=x+7
b) A1=(x+7)²
3)a) A2=aire ABCD-aire EBHI = (x+7)²-36
b) (x+7)²-36 = (x+7)²-6² = (x+7-6)(x+7+6)=(x+1)(x+13) car a²-b²=(a+b)(a-b)
4)a) AE=x+1
b) A3=(x+1)²
5)A2=4A3 ⇒ (x+7)²-36 = 4(x+1)²
si x=3 , (x+7)²-36 = 100-36=64 et 4(x+1)²=4(4)²=4*16=64
A2=4A3 quand x=3
6) A2=(x+7)²-36 = x²+14x+49-36=x²+14x+13
A3=(x+1)² = x²+2x+1
