Question

Write the equation of the line given the slope and a point on the line. m = -4, point (2, -5)

Answer 1

Use the point-slope formula:
-5=(-4)(2)+b
-5=-8+b
b=-13

y=-4x-13

Answer 2

Alright, using the formula I used before, y = mx + b, plug in what you know.

In this case, using the slope m = -4, we get:

y = -4x + b

Now, use the point you have (x, y) - > (2, -5), and plug it into the equation.

-5 = -8 + b.

Solve for b by adding 8 to both sides, and b = 3. Now, go back to the beginning function I wrote y = mx + b. In a linear equation, the slope and y intercept never change. So you write the equation with both those values plugged in.

y = -4x + 3.

Or, y = 3 - 4x

Answer 3

Sniping, you have a miscalculation in your third line. It should be b = 3, since -5 + 8 = 3