What is the equation of a line, in point-slope form, that passes through (-4, -1) and has a slope of (5, 7)
Mathematics · Middle School · Wed Jan 13 2021
Answered on
Point slope form: y – y1 = m(x – x1)
Use slope formula: m = (y2 - y1)/(x2 - x1)
The two points you are given (-4,-1) and (5,7) can be plugged into the formula.
(-4,-1) = (x1, y1)
(5,7) = (x2, y2)
put the value in equation and solve for slope:
m = (7 + 1)/(5 - (-4))
m = 8/9
Slope = 8/9
Now, put the value of slope in the equstion, and a point given (here, use (-4,-1) because that's the one in the answer choices) into the slope-intercept formula:
y – y1 = m(x – x1)
y -(-1) = (8/9)(x - (-4))
y + 1 = (8/9)(x + 4) (Answer)