They are: x and y and the expression can be simplified to 6xy
'y' is a variable. '15' is not. [ y+15 ] is an expression in one variable.
Terme und variablen (2)
In the expression 5 + y + 8, y is a variable. We know how much 5 and 8 are, those are definite quantities. Only y has an unknown, and hence variable value.
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5 less than y
The phrase is "y reduced by 5".
They are: x and y and the expression can be simplified to 6xy
In the expression y+15, there is one variable, the "y."
'y' is a variable. '15' is not. [ y+15 ] is an expression in one variable.
Terme und variablen (2)
y
4y + 9The variable is Y. The variable is the letter (the unknown amount)
In the expression 5 + y + 8, y is a variable. We know how much 5 and 8 are, those are definite quantities. Only y has an unknown, and hence variable value.
You may be referring to an independent variable, which is a quantity in a mathematical expression whose value does not depend upon variations in other quantities in that mathematical expression. For example, in the expression y=2x the variable y depends on the value of x and so is not independent, while in the expression z=x+y the variable z is dependent, but the variables x and y are both independent.
17 - y
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