Question

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

Answer 1

Answer: y = -5x - 15

Step-by-step explanation:

What we know:

• The line has a slope of -5
• The line passes through (-4,5)
• The formula for slope-intercept form is y=mx+b

How to solve:

By substituting the point and slope we know, we can solve for b (the y-intercept.) This will allow us to write the full equation, as we already know the slope.

Process:

Solving for B

Set up equation y = mx + b

Substitute 5 = -5(-4) + b

Simplify 5 = 20 + b

-20 -20

Solve -15 = b

Writing the Equation

Set up equation y = mx + b

Substitute y = -5x - 15

Solve y = -5x - 15

Answer: y = -5x - 15

Check:

We can check if our equation is right by graphing it. In this graph, you can see it has a slope of -5 and goes through the point (-4,5). Therefore, our answer is correct:

Answer 2

Answer:
y = -5x - 15

Step-by-step explanation:
5 = -5(-4) + b
5 = 20 + b
-15 = b

y = -5x - 15