1
x≠0;x≠3
10x-8x+24-x²+3x=0
x²-5x-24=0
x1+x2=5 U x1*x2=-24
x1=-3 U x2=8
2
x≠0;x≠-3
20x+60+20x-3x²-9x=0
3x²-31x-60=0
D=961+720=1681
x1=(31-41)/6=-5/3
x2=(31+41)/6=12
3
x≠3;x≠-3
8x+24+8x-24-5x²+45=0
5x²-16x-45=0
D=256+900=1156
x1=(16-34)/10=-1,8
x2=(16+34)/10=5
4
x≠0;x≠5
2x+14x-70-3x²+15x=0
3x²-31+70=0
D=961-840=121
x1=(31-11)/6=10/3
x2=(31+11)/6=7
5
x≠6;x≠-3/4
12x²+25x+12-x²+8x-12=0
11x²+33x=0
11x(x+3)=0
x1=0
x2=-3