bonjour,
exo 1 : je te laisse écrire les justifications
1) BD :
BD² = BC²+DC
= 6²+8²
BD = √100 = 10m
2) (MP)//(BD)→thales
AP/AD=AM/AB=PM/BD
AP/6 =x/8
AP = 6x/8 = 3x/4
3) MP² = AM²+AP²
= x²+(3x/4)²
= x²+9x²/16
= 25x²/16
MP = √25x²/16 = 5x/4
4) DP = AD-AP
= 6-(3x/4)
MB = AB-AM
= 8-x
5) P AMP
f(x) = x+(3x/4)+(5x/4) = (4x+3x+5x)/4 = 12x/4 = 3x
P MBDP
g(x) = (5x/4)+8-x+10+6-(3x/4)
= (2x/4)-x+24
= (2x-4x)/4+24
= -2x/4 + 24
= 24-[tex] \frac{x}{2} [/tex]
6) f(4) =3x = 3*4 = 12
g(4) = 24-x/2 = 24-4/2 = 22