Question

If y = 5x − 4, which of the following sets represents possible inputs and outputs of the function, represented as ordered pairs?

{(0, −4), (2, 6), (4, 20)}
{(0, −4), (2, 6), (4, 16)}
{(0, 4), (2, 6), (4, 16)}
{(0, 4), (2, −6), (4, 20)}

Answer 1

{(0, −4), (2, 6), (4, 16)}

Explanation:

Since, in an order pair the first value represents the input value and second value represents the output value,

i.e. (a, b) is an order pair ⇒ a = input, b = output,

Here, the given function,

`y = 5x - 4`

(i) For the relation {(0, −4), (2, 6), (4, 20)},

At ( 4, 20), y = 5(4) - 4 = 20 - 4 = 16 ( false ),

(ii) For the relation {(0, −4), (2, 6), (4, 16)},

At (0, −4), y = 5(0) - 4 = -4 ( true ),

At (2, 6), y = 5(2) - 4 = 10 - 4 = 6 ( true ),

At ( 4, 16), y = 5(4) - 4 = 20 - 4 = 16 ( true ),

(iii) For the relation {(0, 4), (2, 6), (4, 20)},

At (0, 4), y = 5(0) - 4 = -4 ( false ),

(iv) For the relation {(0, 4), (2, −6), (4, 20)}

At (2, -6), y = 5(2) - 4 = 6 ( false ),

Hence, (ii) represents possible inputs and outputs of the function.

Answer 2

{(0, −4), (2, 6), (4, 16)}

EXPLANATION

The given function is

`y = 5x - 4`

when x=0,

y=5(0)-4

y=-4

(0,-4)

When x=2,

y=5(2)-4

y=6

(2,6)

When x=4

y=5(4)-4

y=16

(4,16)

The correct choice is

{(0, −4), (2, 6), (4, 16)}