Question

What is the y-intercept of the function, represented by the table of values below

Answer 1

D

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 ) = (- 2, 15) and (x₂, y₂ ) = (1, 6) ← 2 ordered pairs from the table

m =
`(6-15)/(1-(-2))` =
`(-9)/(1+2)` =
`(-9)/(3)` = - 3 , then

y = - 3x + c ← is the partial equation

To find c substitute any ordered pair from the table into the partial equation

Using (2, - 3 ) , then

- 3 = - 6 + c ⇒ c = - 3 + 6 = 3

The y- intercept c = 3 → D