# What is the y intercept for a line with point (7,9) slope 1/2?

##### 1 Answer
Oct 3, 2015

$b = 5.5$

#### Explanation:

We can easily find the y-intercept by finding the equation of the line in the slope-intercept form $y = m x + b$, where $m$ is the slope and $b$ is the y-intercept.

We are given the slope $\frac{1}{2}$, which we can substitute to $m$.
$y = m x + b$
$y = \frac{1}{2} x + b$

Now to solve for $b$ we will make use of the point (7,9). We will simply substitute them into $x$ and $y$.
$9 = \frac{1}{2} \left(7\right) + b$
$9 = 3.5 + b$
$9 - 3.5 = b$
$\textcolor{red}{b = 5.5}$