The relationship is a function. A function is an equation of graph that has no repeated x values. In this graph, each x value has a different y value, whether it's (1, 70) or (9,95)
If Rachel gets anything other than a 95, the x value of 2 will have more than one y value: 95 and whatever grade Rachel gets. Therefore it will no longer be a function.
In factorizing its 36 my dude. Im sure just took the test
Find the intersection point between the 2 restraint equations:

Substitute back in to find y-value:

P is maximized at point (12,6)