Question

What is an equation of the line whose graph is shown? A. y = -x B. y = 2x C. y = x D. y = 2

Answer 1

C

Explanation:

The equation of a line passing through the origin is

y = mx ( m is the slope )

Calculate m using the slope formula

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

with (x₁, y₁ ) = (- 1, - 1) and (x₂, y₂ ) = (1, 1)

m =
`(1+1)/(1+1)` =
`(2)/(2)` = 1, thus

y = x ← equation of line