$y=3x^2+2x^2+x$

$y=(x-1)^2(x-2)^2$

$y=x^2+2^x$

$y=3x-1$

$y=(x-2)^2-1$

$y^2=(x-2)^2-1$

$y=\frac{1}{x^2}+\frac{1}{x}+\frac{1}{2}$

$y=\frac{1}{2}x+\frac{1}{3}$

$y=x$

$y=-7$