Answer:
The inequality is
It solves to
She needs at least 16 more points.
=========================================================
Further Explanation:
"At least 80" means "80 or more"
In other words, the lowest grade she can get is 80
x = number of points she needs
x+64 = number of points she has, after adding on the earlier 64 points
The x+64 must be 80 or larger. So the inequality to set up is
You had the right idea, but need to flip the inequality sign.
To solve this inequality, you subtract 64 from both sides and you should end up with
This says she needs at least more 16 points to go with the 64 points she already has.