Question

The coordinate pairs (-5, -11), (0, -1), and (5, 9) are solutions to which function?

a. f(x)=3x-1
b. f(x)=2x+1
c. f(x)=3x-6
d. f(x)=2x-1

Answer 1

You have to probe each function until you find the right one.

1) f(x) = 3x - 1
x f(x) = 3x - 1

-5 3(-5) - 1 = -15 - 1 = - 16 => it is not

2) f(x) = 2x + 1

x f(x) = 2x + 1

-5 2(-5) + 1 = -10 + 1 = - 9 => it is not

3) f(x) = 3x - 6

x f(x) = 3x - 6

-5 3(-5) - 6 = - 15 - 6 = - 21 => it is not

4) f(x) = 2x - 1

x f(x) = 2x - 1

- 5 2(-5) - 1 = -10 - 1 = -11 => point (-5, -11) => right

0 2(0) - 1 = 0 - 1 = - 1 => pont ( 0, - 1) => right

5 2(5) - 1 = 10 - 1 = 9 => point (5, 9) => right

Therefore the answer is the option d. f(x) = 2x - 1