What is an equation of the line that passes through the points (0,8) and (−5,4)? Put your answer in fully reduced form.

Answer 1

To write the equation of a line you need the slope and at least one point.

We are given 2 points so we can find the slope = m = (y2 - y1) / (x2 - x1) = (4-8) /(-5 - 0) = -4 / -5 = 4/5 = 0.8

Now choose a point and write it in "point slope" form or "slope-intercept" form

Using (0,8)

Point-slope: [ y-y1 = m(x - x1) ] y-8 = (0.8)(x-0) y-8 = 0.8x y = 0.8x + 8

Slope-intercept: [ y = mx + b } y = 0.8x + b but now we need to find "b". So plug on our coordinates from the point (0,8) and get 8 = (0.8)(0) + b 8 = b Now we know that b = 8, can write y = 0.8x + 8

(same as first one simplified to!)