bonjour
exo1
A=3(1/5+x)+(1/2)(2x-1/5)-5x/3-4/7
A=3/5+3x+x-1/10-5x/3-4/7
A=4x-5x/3+3/5-1/10-4/7
A=(12-5)x/3+(42-7-40)/70=7x/3-1/14
B=(1/6)(x/5-1/12)+(1/15)(-5-x/2)+1/72
B=x/30-1/72-1/3-x/30+1/72=-1/3
C=3-(2/7)(1-7t)+3[2t-(t-4)+2/21]
C=3-2/7+2t+3(2t-t+4+2/21)
C=3-2/7+2t+3t+12+2/21
C=5t+15-6/21+2/21=5t+15-4/21=5t+(315-4)/21=5t+311/21
exo2
1/ T=(5x+2)(4-7x)+(5x-2)(5x+2)
T=(5x+2)[(4-7x)+(5x-2)]
T=(5x+2)(4-7x+5x-2)=(5x+2)(-2x+2)=-2(5x+2)(x-1)
2/ T=20x-35x²+8-14x+25x²-4
T=-10x²+6x+4
3/ T(-2/5)=-10*(-2/5)²+6(-2/5)+4=-10*4/25-12/5+4=-8/5-12/5+4=-20/5+4=0
T(4/3)=-10(4/3)²+6*4/3+4= -10*16/9+24/3+4= -160/9+8+4 = -160/9+12 = -160/9+108/9=-52/9
exo3
A=(x+1)(2x-1)-2x
1/ A=2x²-x+2x-1-2x=x-1
2/ A=100 001* 199 999 -2*100 000²
ici, x=100 000
donc A=100 000-1=99 999
