I kind of agree with Silky Smooth.
I remember doing Year 11 and 12 texts back in high school having only 'answers' to the questions given. (by that : I mean just numbers at the back of the book to compare against)
I think you need step by step worked out solutions in order to be good at maths. Having examples from textbooks help as well but its a 'process' in getting to the answer that troubles a student. When you see a multitude of questions and their 'step by step ' process you get better as a student.
I used a text by O.T Lee (which came with a fully worked out solutions manual I think it was around $100 back in the day, in comparison to the textbook which was about $70) back in my state and it helped improved my maths more so than say getting a tutor, who would also be able to explain it step by step.
But no doubt after you have mastered alot of questions you should be able to do further questions without needing to refer to a textbook. But in the initial stages of learning a new topic, you need solutions to get better.
I once tutored Physics (which I don't do anymore), and the parents were critical of me giving answers to certain questions from a text. Everyone has a different way of learning but I guess what I should have told them was 'it was for the benefit of their learning', which I didn't get the chance to explain to them. (I think about it now and I say I didn't do too much wrong, I think they failed to see my side of things or I should have emphasized a bit better what the point of giving him answers was for). Having tutored a number of students I provide my students with worksheets+answers, exam papers, tests, theoretical notes which isn't being too unreasonable. (in fact most of my students demand more material....I found that more the case in NSW since there are a wide variety of texts to use, every student wants any slight advantage over their classmates) I can totally understand if you aren't given solutions but can work a way of getting to the answer (by reading up more on the topic, watching videos, checking with friends/teachers etc) it makes your understanding a bit better than simply looking up the solutions.