$f(x)=-4x+2$f(x)=-4x+2

$f(x)=-4x-2$f(x)=-4x-2

$\displaystyle f(x)= \frac{1}{4}x-2$\displaystyle f(x)= \frac{1}{4}x-2

$\displaystyle f(x)=- \frac{1}{4}x-2$\displaystyle f(x)=- \frac{1}{4}x-2