Find the Slope and y-intercept (-1,1) , (3,9)

$(- 1, 1)$ , $(3, 9)$

Find the value of the slope.

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.

$m = \frac{9 - (1)}{3 - (- 1)}$

Simplify.

Simplify the numerator.

Multiply $- 1$ by $1$ .

$m = \frac{9 - 1}{3 - (- 1)}$

Subtract $1$ from $9$ .

$m = \frac{8}{3 - (- 1)}$

Simplify the denominator.

Multiply $- 1$ by $- 1$ .

$m = \frac{8}{3 + 1}$

Add $3$ and $1$ .

$m = \frac{8}{4}$

Divide $8$ by $4$ .

$m = 2$

Find the value of the y-intercept.

Substitute the value of $m$ into the slope-intercept form of the equation, $y = m x + b$ .

$y = (2) \cdot x + b$

Substitute the value of $x$ into the slope-intercept form of the equation, $y = m x + b$ .

$y = (2) \cdot (- 1) + b$

Substitute the value of $y$ into the slope-intercept form of the equation, $y = m x + b$ .

$1 = (2) \cdot (- 1) + b$

Rewrite the equation as $(2) \cdot (- 1) + b = 1$ .

$(2) \cdot (- 1) + b = 1$

Multiply $2$ by $- 1$ .

$- 2 + b = 1$

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

Add $2$ to both sides of the equation.

$b = 1 + 2$

Add $1$ and $2$ .

$b = 3$

List the slope and y-intercept.

Slope: $2$

y-intercept: $(0, 3)$

Find the Slope and y-intercept (-1,1) , (3,9)

Related Questions

Support LCMGCF.com by disabling your adblocker.