1
6x-x=-13
5x=-13
x=-13:5
x=-2,6
2
9+30x-100=2
3x=2+91
30x=93
x=93:30
x=3,1
3
6(9x+6)+3*42=7*7x
54x+36+126-49x=0
5x=-162
x=-162:5
x=-32,4
4
x-3-4x-16=20-5x-1
-3x+5x=19+19
2x=38
x=38:2
x=19
5
x²-10x+25-x²-20x-100=0
-30x=75
x=75:(-30)
x=-2,5
6
4x(x-5)=0
x=0
x-5=0
x=5
7
16x²=16
x²=1
x=-1
x=1
8
x²+7x-18=0
x1+x2=-7 U x1*x2=-18
x1=-9 U x2=2
9
x²-9x+18=0
x1+x2=9 U x1*x2=18
x1=3 U x2=6
10
-4x-1=0
4x=-1
x=-1/4
5x-2=0
5x=2
x=2/5