The phrase "a demanding and complex" is correct and usable in written English.
It can be used to describe a task, situation, or subject that requires significant effort and is intricate in nature.
Example: "The project we are undertaking is a demanding and complex endeavor that will require careful planning and execution."
Alternatives: "challenging and intricate" or "difficult and multifaceted".
On the other hand, given that teaching is such a demanding and complex job, it would be bizarre if there was not a wide gap between the best performers and the worst.
But we also believe that faking it is a demanding and complex task for the combination of all the existent components (Tett et al. 2012).
The proposal and realization of such distributed control system represents a demanding and complex task of real time control for track optimizing with minimal fuel consumption.
5 7 In the UK, and elsewhere, primary care based administrators (most commonly frontline receptionists) work in a demanding and complex role that involves communicating with patients and performing a variety of office duties, many of which have safety importance.
The honest conclusion from this study is that tight glycaemic control is a demanding and complex intervention, making it hard to steer blood glucose levels in the right stratum.
The bridge would be a demanding and technically complex project, however, and at first there were doubts about who would be willing to undertake it.
The assessment of a building's energy performance as a design factor in the early design stages is a very demanding and complex procedure.
In order to effectively design nearly Zero Energy Buildings, the assessment of energy performance in the early design stages through simulation is an important, although very demanding and complex, procedure.
While the number of burglary, robbery and driving offences being prosecuted had declined sharply in recent years, Wright told MPs on the justice select committee, there had been a marked increase in more demanding and complex cases, especially those involving terrorism and sexual offences.
The CHEX had a detrimental effect on subjective workload as participants judged that their tasks were more demanding and complex and required more mental and perceptual activities in the presence of the tool than in its absence.
I was pretty terrified in the 1970s, when I'd no idea how much more demanding and complex life was going to get.
