How do I write 243 ina factor tree and then give the answer in index form
:)

You need to find the lowest prime number that divides into 243 exactly. Try 2 first, then 3, then 5 etc until you find one that divides with no remainder. You should find that 3 divides into 243 81 times, then you need to repeat the process with 81 until you get to a stage where you are left with a prime number.

All the prime numbers that you divided by are the prime factors. Then to write it in index form you just gather together like terms, for instance 16 has prime notation 2*2*2*2 or in index notation .

Let me know what answer you get and I'll check it.