Question

Which of the following rules represents the set of ordered pairs? {(2, 5), (3, 7), (5, 11),

a.ƒ(x ) = 2x + 1

b.ƒ(x ) = x + 5

c.ƒ(x ) = -x + 10

Answer 1

I think the answer is a.

Answer 2

a

Explanation:

To determine which ordered pair is a solution to the functions

Substitute the x- coordinate into the right side and if the value is equal to the y- coordinate then it is a solution.

(a) f(x) = 2x + 1

f(2) = (2 × 2) + 1 = 4 + 1 = 5 ⇒ (2,5) is a solution

f(3) = (2 × 3) + 1 = 6 + 1 = 7 ⇒ (3, 7) is a solution

f(5) = (2 × 5) + 1 = 10 + 1 = 11 ⇒ (5, 11) is a solution

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(b) f(x) = x + 5

f(2) = 2 + 5 = 7 ⇒ (2, 5) is not a solution

f(3) = 3 + 5 = 8 ⇒ (3, 7) is not a solution

f(5) = 5 + 5 = 10 ⇒ (5, 11) is not a solution

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(c) f(x) = - x + 10

f(2) = - 2 + 10 = 8 ⇒ (2, 5) is not a solution

f(3) = - 3 + 10 = 7 ⇒ (3, 7) is a solution

f(5) = - 5 + 10 = 5 ⇒ (5, 11) is not a solution

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The only function representing the ordered pairs is (a)