Answer
$\int_{-7}^{5} (x^2-3x) dx$.
Work Step by Step
By using the definition of the definite integral, P is a partition of [-7,5], therefore the lower and upper limits of the integration are -7 and 5. $f(c_{k})=(c_{k}^2-3c_{k})$ is the function in the additive of the Riemann sums, therefore $f(x)=(x^2-3x)$. Therefore the solution is: $\int_{-7}^{5} (x^2-3x) dx$.