y=ax²+bx+c; a=3; b=-1\cdot -2\cdot a \to b=6
y=ax²+bx+c; a=2; b= ...
y=ax²+bx+c; a=-2; b= ...
y=ax²+bx+c; a=3; b= ...
y=ax²+bx+c; a=1; b= ...
y=ax²+bx+c; a=-1; b= ...
y=ax²+bx+c; a=-3; b= ...