Question

Which points are on the graph of the function rule ƒ(x) = 10 – 4x? ( –18, 2), ( –10, 0), ( –2, –2) (18, –2), (10, 0), (2, 2) (–2, 18), (0, 10), (2, 2) (2, –18), (0, –10), ( –2, –2)

Answer 1

(2, 2 ), (- 2, 18 ), (0, 10 )

substitute the x-coordinate of each point into f(x) and if the value is equal to the y-coordinate then it is on the graph of f(x)

(- 18, 2 ) ⇒ y = 10 + 72= 82 ≠ 2

(- 10, 0 ) ⇔ y = 10 + 40 = 50 ≠ 0

(- 2, - 2 )⇒ y = 10 + 8 = 18 ≠ 2

(18, - 2 ) ⇒ y = 10 - 72 = - 62 ≠ - 2

(2, 2 ) ⇒ y = 10 - 8 = 2 ⇒ (2, 2 ) is on graph

(- 2, 18 ) ⇒ y = 10 + 8 = 18 ⇒ (- 2, 18 ) is on graph

(0, 10 )⇒ y = 10 - 0 = 10 ⇒ (0, 10 ) is on graph

(2, - 18 ) ⇒ y = 10 - 8 ≠ - 18