## Slope intercept form of line through (4, -2) and (3, 8)

Simplificatation, evaluation, linear equations, linear graphs, linear inequalities, basic word problems, etc.

### Slope intercept form of line through (4, -2) and (3, 8)

5. Give the slope-intercept form of the equation for the line on which these two points lie: (4, -2) and (3, 8)
tomihle

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Joined: Mon Jun 01, 2009 6:58 pm

### Re: Slope intercept

tomihle wrote:5. Give the slope-intercept form of the equation for the line on which these two points lie: (4, -2) and (3, 8)

5.1) We need to find the slope. $m\,=\frac{y_2 - y_1}{x_2 - x_1}$. Plug the y-coordinates and the x-coordinates into the formula.
That would be either
$m\,=\frac{8\, -\, (-2)}{3\,-\,4}$ or $m\,=\frac{-2\, -\,8}{4\,-\,3}$. Hint: The answer is a negative integer.

5.2) Set up the equation, $y\,=\,mx\,+\,b$. Plug in the answer from 5.1 for $m$. Then choose either point. If you choose (4, -2), then plug in 4 for $x$ and -2 for $y$. Otherwise choose (3,8); plug in 3 for $x$ and 8 for $y$. Either point will yield the same result, next step.

5.3) Solve equation 5.2 for $b$.

5.4) Set up the equation $y\,=\,mx\,+\,b$ again. Plug in the answer from 5.1 for $m$. Plug in the answer from 5.3 from 5.1 for $b$. Leave the $x$ and $y$ alone!