Greetings!
An easy way to remember this is along the corridoor, up the stairs!
That being said the first number, -3.5, is a negative which means it will be on the left hand side of the x axis. Simply look for the point that goes along this line.
And the second number, which is the point on the y axis, is a positive number which means it is above the x axis. Simply look for the point that is along y = 4
This means you can find the point, which in this case is Z.
Hope this helps!
