x2−8x−12=0x^{2}-8 x-12=0x2−8x−12=0
x2−2x−15=0x^{2}-2 x-15=0x2−2x−15=0
x2+12x+15=0x^{2}+12 x+15=0x2+12x+15=0
x2+15x+2=0x^{2}+15 x+2=0x2+15x+2=0
