Given:
Noah receives 40 points rewards for signing up
And for each visit 4.5 point
So, the total points will be :
[tex]4.5v+40[/tex]
He need at least 145 points
so, the relation will be :
[tex]4.5v+40\ge145[/tex]
Or can be written as :
[tex]145\le40+4.5v[/tex]
