Answer
Fill the blank with:
linear
Work Step by Step
$y=ax+b$ is an equation for a straight line,
$f(x)=ax+b$ is a linear function (the graph is a line),
The form $ax+b$ is called linear, and $ax+b=0$ is a linear equation.
(See the first definition on the first page of this section)
Fill the blank with: linear
