Question

Find the equation of the line. Use exact numbers​

Answer 1

y = - 3x + 7

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Calculate m using the slope formula

m =
`(y_(2)-y_(1) )/(x_(2)-x_(1) )`

with (x₁, y₁ ) = (0, 7) and (x₂, y₂ ) = (2, 1) ← 2 points on the line

m =
`(1-7)/(2-0)` =
`(-6)/(2)` = - 3

The line crosses the y- axis at (0, 7 ) ⇒ c = 7

y = - 3x + 7 ← equation of line

Answer 2

y = -3x + 7

Explanation:

Again, pick a random point. I chose point (0,7). Then, we see how many units it takes to reach the next point. Let's try it. First, we move down 3 units, rise = -3, then move right 1 unit, run 1. So slope is rise over run, so -3/1 = -3. Then, for the y intercept, just see the y value when x = 0.