Exercise 2 Page 229

Equations in slope-intercept form follow a certain format. In this form, $m$ is the slope and $b$ is the $y\text{-}$intercept. The line has a slope of $2$ which means that we can substitute $m=2.$ To write a complete equation for this line, we also need to determine the $y\text{-}$intercept $b.$ We can do that by substituting the given point $(2,4)$ into the equation and solving for $b.$ Now that we have both slope and $y\text{-}$intercept we can write the final equation.