Explanation:
f(x) is essentially a fancy way to say y. The graphs y = 7x + 2 is equivalent to f(x) = 7x + 2. The value of a function is the x value.
Here is an example problem:
Find the value of f(2) = 5x + 10
f(2) = 5(2) + 10
f(2) = 10 + 10
f(2) = 20
The value of the function would be 20 when x =2. the question 'find the value where x = 2 in the equation y = 5x + 10' the answer would be y = 20.