Compute the given question

Question- Since the tubes and shell are connected, their final lengths must be the same. Copper has a larger linear expansion coefficient; therefore the tubes will be longer if they could expand freely. Let the amount by which the tubes are shortened be Delta Lt and the amount by which the shell is extended be Delta Ls. There final lengths must be the same and the strain in the tube times its Young's modulus must equal the strain in the shell times its Young's modulus.

Part 1- Solve for Delta Lt and Delta Ls and calculate the final lengths and the stress in the tubes and shell. Which one is under compressive stress and which one is under tensile stress?

I want expert's assistance to determine the final lengths and the stress in the tubes and shell.