Determine if each function is increasing or decreasing

$7.$f $($ x$)=4$x$+3$

$9.$ a $($ x$)=5-2$x

$11.$ h $($ x$)=-2$x$+4$

$$

$13.$ j $($ x$)=1$ x $-3$

$2$

$15.$ n $($ x$)=-1$ x $-2$

$3$