$\displaystyle y= \frac{1}{4}x+1$\displaystyle y= \frac{1}{4}x+1

$\displaystyle y=- \frac{1}{4}x-7$\displaystyle y=- \frac{1}{4}x-7

$y=4x-1$y=4x-1

$y=-4x+7$y=-4x+7