1) a)5x+3=4+4x
5x+3-3=4+4x-3
5x=7+4x
5x-4x=7+4x-4x
x-=7
b)7x-1=4x+12.5
7x-1+1=4x+12.5+1
7x=4x+13.5
7x-4x=4x+13.5-4x
3x=13.5
3x/3=13.5/3
x=4.5
c)4-(5-x)=9x+2
4-5+x=9x+2
-1+x=9x+2
-1+x+1=9x+2+1
x=9x+3
x-9x=9x+3-9x
-8x=3
-8x/-8=3/-8
x=-5
d)(x+3)-(2x-1)=8
x+3-2x+1=8
-x+4=8
-x+4-4=8-4
-x=4
x=-4
e)(x+5)(4x+2)=0
x*4x+x*2+5*4x+5*2=0
4x au carré+2x+20x+20=0
4xau carré+22x+20=0
4xau carré+22x+20-20=0-20
4xau carré+22x=-20
4xau carré/4+22x/22=-20/4/22
xau carré+x=5.5
Après je sais pas
f)x(x+9)=0
xau carré+9x=0
xau carré+9x/9=0/9
xau carré+x=0/9