# How do you know if Points P(5,7) and Q(-1,1) lie on the graph of y=x+2?

##### 1 Answer

Jan 8, 2016

by substituting the coordinate points into the equation and checking that the equation is satisfied ie. made true.

#### Explanation:

using P(5 , 7 ) : substitute x = 5 into the equation and if it lies on the graph then y should = 7.

x = 5 gives y = 5 + 2 = 7 hence P lies on the graph.

similarly for point Q(-1 , 1 )

x = - 1 gives y = - 1 + 2 = 1 hence Q lies on the graph.

the following graph of y = x + 2 should illustrate this.

graph{x + 2 [-20, 20, -10, 10]}