It’s a 90 degree clockwise rotation as coordinates become (y,-x).
The first one 6 second 8 but it’s funny
He has to buy 4 packs. If you divide 23 by 6, you get 3.833 but you can’t buy a fraction of a pack so you have to round up and buy 4 packs. Hope this made sense; I can explain further if needed!
Did you ever find the answer?
Take some points
As here < sign present line will be dashed and shading should be done below the line
So
Graph attached