$\displaystyle f(x)=- \frac{1}{3}x+ \frac{7}{3}$\displaystyle f(x)=- \frac{1}{3}x+ \frac{7}{3}

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

$f(x)=-3x+7$f(x)=-3x+7

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