Find the Equation with a Point and Slope What is the equation of the line that passes through the point (-1,4) and has a slope of -5 ?

What is the equation of the line that passes through the point $(- 1, 4)$ and has a slope of $- 5$ ?

Step 1

Find the value of $b$ using the formula for the equation of a line.

Use the formula for the equation of a line to find $b$ .

$y = m x + b$

Substitute the value of $m$ into the equation.

$y = (- 5) \cdot x + b$

Substitute the value of $x$ into the equation.

$y = (- 5) \cdot (- 1) + b$

Substitute the value of $y$ into the equation.

$4 = (- 5) \cdot (- 1) + b$

Find the value of $b$ .

Rewrite the equation as $(- 5) \cdot (- 1) + b = 4$ .

$(- 5) \cdot (- 1) + b = 4$

Multiply $- 5$ by $- 1$ .

$5 + b = 4$

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

Subtract $5$ from both sides of the equation.

$b = 4 - 5$

Subtract $5$ from $4$ .

$b = - 1$

Step 2

Now that the values of $m$ (slope) and $b$ (y-intercept) are known, substitute them into $y = m x + b$ to find the equation of the line.

$y = - 5 x - 1$

Step 3