Question

Which equation represents the graphed function?

A : y = -2x + 3
B : y = 2x + 3
C : y = 1/2x + 3
D : y = -1/2x + 3

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 ) = (0, 3) and (x₂, y₂ ) = (1, 1) ← 2 points on the line

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

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

y = - 2x + 3 ← equation of line