Question

What is the equation of the blue line?

Answer 1

y = 2x + 3

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 ) = (1, 5) and (x₂, y₂ ) = (3, 9) ← 2 points on the line

m =
`(9-5)/(3-1)` =
`(4)/(2)` = 2

the line crosses the y- axis at (0, 3 ) ⇒ c = 3

y = 2x + 3 ← equation of line