Question

Determine whether each point lies on the graph of the equation. y = 9 − x

(a) (5, 2)
yes
no
(b) (9, 0)
yes
no

Answer 1

a) y = 9 - 5
=4
2 is not equal to 4, hence it does not lies on the graph. Ans: No

b) y = 9 - 9
=0
Since 0 = 0, it lies on the graph of the equation. Ans: Yes

*Always sub in the values to check whether it lies on the graph.

Answer 2

For this case we have the following equation:

`y = 9 - x`

To determine if the points belong to the line, equality must be met.

We have then:

For (5, 2):

`5 = 9 - 2`

`5 = 7`

Equality is not met and therefore, this point does not belong to the line.

For (9, 0):

`0 = 9 - 9`

`0 = 0`

The equality is fulfilled and therefore, the point belongs to the line.

Answer:

(a) (5, 2), no

(b) (9, 0), yes