You are given $f(x) = 7(3)^{x-2} - 4$. Substitute the appropriate $x$-value from the row with $c$ into this formula.

After substituting, first simplify the exponent $x-2$, then compute the power of 3, then multiply by 7, and only at the end apply the $-4$.

In Desmos, type f(x) = 7*3^(x-2) - 4 so the calculator stores the function $f(x) = 7(3)^{x-2} - 4$.

In a new line, type f(4) (or create a table for $f(x)$ and enter $4$ in the $x$-column). The value that Desmos gives for $f(4)$ is the constant $c$ in the table.

From the table, the value $c$ is the output of the function when $x=4$. In other words, $c = f(4)$ for the function

So the problem is asking you to compute $f(4)$.

Replace $x$ with $4$ in the expression for $f(x)$:

Now simplify the exponent $4 - 2$ first, before dealing with the power or multiplication.

Compute the exponent:

so the expression becomes

Now evaluate $3^2$:

so we have

Multiply first:

Now subtract $4$:

Since $c = f(4)$, the value of $c$ is 59.