What is the procedure for straight leg raising test?

Questions

Whаt is the prоcedure fоr strаight leg rаising test?

Simplify the expressiоn. (6b2+3b3-4b)+(8b2-7b3+7b){"versiоn":"1.1","mаth":"(6b2+3b3-4b)+(8b2-7b3+7b)"}