16x²+8x+1=12y
x²+8x+16=3y
y=(x²+8x+16)/3
16x²+8x+1=12*(x²+8x+16)/3
16x²+8x+1=(12x²+96x+192)/3
3(16x²+8x+1)=12x²+96x+192
48x²+24x+3=12x²+96x+192
48x²+24x+3-12x²-96x-192=0
36x²-72x-189=0
D=5184+27216=32400=180²
x₁=(72+180)/72=3,5
x₂=(72-180)/72=-1,5
y₁=(3,5²+8*3,5+16)/3=(12,25+28+16)/3=56,25/3=18,75
y₂=(1,5²+8*1,5+16)/3=(2,25+12+16)/3=30,25/3=10,1