## Step-by-step explanation

Problem to solve:

Learn how to solve calculus problems step by step online.

$\begin{matrix}u=a-10 \\ du=da\end{matrix}$

Learn how to solve calculus problems step by step online. Integrate int((a-10)*(a+10))da with respect to a. Solve the integral \int\left(a-10\right)\left(a+10\right)da applying u-substitution. Let u and du be. Rewriting a in terms of u. Substituting u, da and a in the integral and simplify. The integral of the sum of two or more functions is equal to the sum of their integrals.