Use the substitution
And, if a picture helps...
Straight continuous lines differentiate/integrate with respect to x, the straight dashed line with respect to the dashed balloon expression - as though it were a variable like u.
Don't integrate - balloontegrate! Balloon Calculus: worked examples from past papers
Yes - and of course the differentiation is the same picture (completed) but read downwards instead of up.
Don't integrate - balloontegrate! http://www.ballooncalculus.org/examples.png