Can you do A-level maths in a year?

I am currently in my Second year of A-level and i have a feeling i did bad in my AS maths, so i would like to retake all the modules in AS while also doing all the modules in A2. Can good grades be achievable if this is done, taking in consideration am also gonna be doing Physics A-level in one year, am gonna start tuition for those subject and give how ever much time needed. Any suggestion and advice will be kindly appreciated.