Question

Use the work shown below to write the equation for a line that has a slope of Negative two-fifths and passes through (15, –2).

y = mx + b

1. Substitute the known values: negative 2 = negative two-fifths (15) + b. 2. Solve for b: negative 2 = negative 6 + b. b = 4.

What is the equation of the line in slope-intercept form?
Negative 2 = negative two-fifths x + 4
y = negative two-fifths (15) + 4
y = negative two-fifths x minus 4
y = negative two-fifths x + 4

Answer 1

y = -\tfrac{2}{5}x + 4

(Check: when x = 15, y = -2/5·15 + 4 = -6 + 4 = -2.)