For the function f(x) = –x + 21, what is the difference quotient?

The difference quotient is the quotient of the difference of the function values, f(x + h) - f(x), and the difference of the input values, (x + h) - x.

Given the function f(x) = -x + 21.

The different quotient will be :

We see that given the function f(x) = -x+21 and two input values of x and x + h, the difference quotient is -1.

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