# How do you write the equation of the line with slope of 2 and passes through the point (4, 9)?

Aug 17, 2016

Substitute the variables in the slope-intercept equation for our slope and point..

#### Explanation:

This is the slope-intercept equation:

$y = m x + b$

The letter $m$ is the slope (2) and the letters $y$ and $x$ are our x- and y-variables (4 and 9, respectively).

Our equation is this:

$9 = 2 \left(4\right) + b$

From here, we solve for $b$:

$2 \cdot 4 = 8$

$9 = 8 + b$

$1 = b$

We now know that $b = 1$, so we can plug it back into our equation to get our answer. Since this is an equation with an infinite number of coordinates on it, the only numbers we're going to put in are the slope and $b$. This is what we get:

$y = 2 x + 1$