Question 978697
How is y involved?  x=1.5 only indicates one number line pointing to a variable assigned to 1.5, maybe more specifically POSITIVE 1.5.  If you want a second variable, y, to be involved, then you may imply another number line at right angle to the first number line, so you have a cartesian coordinate system.  In this case, while x=1.5,  y is all real numbers.