Question

Which of the following is a solution of y - x < -3?

(6, 2)
(2, 6)
(2, -1)

Answer 1

a standard coordinate it written as
(x,y)
so if you had
(6,2) you know that x=6, y=2
you know that y-x<-3
so substitute your values for x and y into this, and if it is less than -3 it is a sollution

Answer 2

for example, if I had a coordinate (1,2)
and I know that y-x<-3

substituting in I would get
2-1<-3
1<-3

this is not true, hence (1,2) is not a solution

Answer 3

2, 6