How to Integrate the Equation (b1-(b1*x/L)+(b2*x/L))^2 with Respect to x?

[krnhseya]

Homework Statement

Integrate

Homework Equations

integrating following equation about dx:
(b1-(b1*x/L)+(b2*x/L))^2

The Attempt at a Solution

I expanded all terms than integrated. I used integration by part to get it down to this but I am curious to see if there's better way to integrate this respect to x

 

[╔(σ_σ)╝]

You could use a substitution u = everything in the brackets.

 

[krnhseya]

right u substitution...thanks!