isnt the power of x supposed to be going up? eg. x^6 + x^7 + x^8 + x^9

If the first term in the brackets is higher in power of x than the second term, your expansion will be in descending powers.

Swap the order and you will get ascending.

If you expand in ascending for the first four terms, you will only get terms until x^3. The second part would not be solveable based on these results.

The question has been set wrongly. You can change “ascending” to “descending”.

P.S. Rewriting my answers in ascending form (x^6, then x^7, then x^8, then x^9) does not make the expression “the first four terms in ascending powers of x”. Instead, it would have been “the final four terms in ascending powers of x”.

I think the question is set like this on purpose. The idea is to expect students to recognise that the terms need to be swapped to become ascending powers.

Edit : just saw 2nd part. That means it should be descending

But even then it would have been the final four terms. The first four terms would not have been able to yield x^7 after multiplying with the 1 - x.

Edit: Failed to see your edit in time.

alright thanks guys

Best is to check with your teacher in class. He/she will probably ask you all to change something in the question.

It could be changing to 'descending' or changing the power of the coefficient to maybe like 3 instead.

Edit :

Unless it's the intention of the phrasing,

i.e to make you expand the expression as per normal to get the first 4 terms and then rearrange it in ascending powers of x.

In typical binomial questions this isn't done. Typically, ascending powers means when you expand, it is already in an ascending fashion

mice