What does in terms of X mean?
Answer: When we explicitly express the dependant variable (Y) in relation to the independent variable (X), we call that as 'Y is expressed in terms of X'.
Let us understand more about algebraic expression and thereby find the answer to the given question.
We we have an equation 14x + 2y = 24 (for an example)
2y = 24 - 14x
y = (24 - 14x)/2
y = 12 - 7x [y is expressed in relation to x explicitly.]
Here y is called the dependant variable and x is called the independent variable.
So, in other words, we mean that y is expressed in terms of x explicitly.
In a broad sense, "in terms of " means defining something like a modification of another thing