Find the Equation Using Point-Slope Formula (-2,3) , (3,-1)

$(- 2, 3)$ , $(3, - 1)$

Step 1

Find the slope of the line between $(- 2, 3)$ and $(3, - 1)$ using $m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}$ , which is the change of $y$ over the change of $x$ .

Slope is equal to the change in $y$ over the change in $x$ , or rise over run.

$m = \frac{change in y}{change in x}$

The change in $x$ is equal to the difference in x-coordinates (also called run), and the change in $y$ is equal to the difference in y-coordinates (also called rise).

$m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}$

Substitute in the values of $x$ and $y$ into the equation to find the slope.

$m = \frac{- 1 - (3)}{3 - (- 2)}$

Simplify.

Simplify the numerator.

Multiply $- 1$ by $3$ .

$m = \frac{- 1 - 3}{3 - (- 2)}$

Subtract $3$ from $- 1$ .

$m = \frac{- 4}{3 - (- 2)}$

Simplify the denominator.

Multiply $- 1$ by $- 2$ .

$m = \frac{- 4}{3 + 2}$

Add $3$ and $2$ .

$m = \frac{- 4}{5}$

Move the negative in front of the fraction.

$m = - \frac{4}{5}$

Step 2

Use the slope $- \frac{4}{5}$ and a given point $(- 2, 3)$ to substitute for $x_{1}$ and $y_{1}$ in the point-slope form $y - y_{1} = m (x - x_{1})$ , which is derived from the slope equation $m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}$ .

$y - (3) = - \frac{4}{5} \cdot (x - (- 2))$

Step 3

Simplify the equation and keep it in point-slope form.

$y - 3 = - \frac{4}{5} \cdot (x + 2)$

Step 4

Solve for $y$ .

Simplify $- \frac{4}{5} \cdot (x + 2)$ .

Rewrite.

$y - 3 = 0 + 0 - \frac{4}{5} \cdot (x + 2)$

Simplify by adding zeros.

$y - 3 = - \frac{4}{5} \cdot (x + 2)$

Apply the distributive property.

$y - 3 = - \frac{4}{5} x - \frac{4}{5} \cdot 2$

Combine $x$ and $\frac{4}{5}$ .

$y - 3 = - \frac{x \cdot 4}{5} - \frac{4}{5} \cdot 2$

Multiply $- \frac{4}{5} \cdot 2$ .

Multiply $2$ by $- 1$ .

$y - 3 = - \frac{x \cdot 4}{5} - 2 (\frac{4}{5})$

Combine $- 2$ and $\frac{4}{5}$ .

$y - 3 = - \frac{x \cdot 4}{5} + \frac{- 2 \cdot 4}{5}$

Multiply $- 2$ by $4$ .

$y - 3 = - \frac{x \cdot 4}{5} + \frac{- 8}{5}$

Simplify each term.

Move $4$ to the left of $x$ .

$y - 3 = - \frac{4 \cdot x}{5} + \frac{- 8}{5}$

Move the negative in front of the fraction.

$y - 3 = - \frac{4 x}{5} - \frac{8}{5}$

Move all terms not containing $y$ to the right side of the equation.

Add $3$ to both sides of the equation.

$y = - \frac{4 x}{5} - \frac{8}{5} + 3$

To write $3$ as a fraction with a common denominator, multiply by $\frac{5}{5}$ .

$y = - \frac{4 x}{5} - \frac{8}{5} + 3 \cdot \frac{5}{5}$

Combine $3$ and $\frac{5}{5}$ .

$y = - \frac{4 x}{5} - \frac{8}{5} + \frac{3 \cdot 5}{5}$

Combine the numerators over the common denominator.

$y = - \frac{4 x}{5} + \frac{- 8 + 3 \cdot 5}{5}$

Simplify the numerator.

Multiply $3$ by $5$ .

$y = - \frac{4 x}{5} + \frac{- 8 + 15}{5}$

Add $- 8$ and $15$ .

$y = - \frac{4 x}{5} + \frac{7}{5}$

Step 5

Reorder terms.

$y = - (\frac{4}{5} x) + \frac{7}{5}$

Step 6

Remove parentheses.

$y = - \frac{4}{5} x + \frac{7}{5}$

Step 7

List the equation in different forms.

Slope-intercept form:

$y = - \frac{4}{5} x + \frac{7}{5}$

Point-slope form:

$y - 3 = - \frac{4}{5} \cdot (x + 2)$

Step 8

Find the Equation Using Point-Slope Formula (-2,3) , (3,-1)

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