It can be.
The y-axis is the metric of the dependent variable.
'y' is a variable. '15' is not. [ y+15 ] is an expression in one variable.
The variable 'x' would equal (8-y)/2. The variable 'y' would equal 8-2x.
To interpret the coefficient of a dummy variable is to follow all of the steps of the equation that is being used as if the dummy variable was a real one.
x=2 and y=3
It is a variable which can take any value.
The dependent variable, y, is equal to 7 less than twice the independent variable, x.
The answer depends on the value of the variable, Y, which is not specified in the question.
The expression -5y + 6 is a combination of a variable (y) and constants (-5 and 6) connected by addition and subtraction operations. To find the answer, you would need a specific value for the variable y. Without knowing the value of y, the expression -5y + 6 cannot be simplified further.
It depends on the problem really because y is a variable and not a constant. It can also mean years so it will equal the amount of years the problem asks.
The variable c times the variable b simply equals cb. Just as the variable x times the variable y would equal xy, and so on.
A mathematical expression in its' most simplistic form, merely assigns a value to a variable. Don't confuse an expression with an equation. An equation requires a solution. An expression cannot be "solved". It only allows you to determine the value of a variable. This is the expression in words "x is equal to 3" (X is the variable which is equal to the constant number 3) This is the expression in numbers "x=3" The expression in words "y is equal to 6" (Y is the variable which is equal to the constant number 6) The expression in numbers is "y=6" I hope you understand now.