Question

What point is a solution of x+2y<4

Answer 1

(2, 4)

(1, 1)

(3, 5)

(-1, 5)

That is the solution of x+2y<4

Answer 2

subtract x
2y<-x+4
divide 2
y<-x/2+4
find line and shade down , including (0,0)

any point there is a solution
(1,1)
(1,-1)
(0,0)
(-pi,pi)