Pre-cal help needed?

Question

were working with bases other than 10 and particularly with hexadecimals. i need to know the answer to

1. subtract FDA (subscript H) and BEF (subscript H)

2. i need 1B9A (subscript H) chanced to base 8.

if you could kinda explain it that would help too

Answer 1

Oh God, no hexadecimals, d**n, those are hard!

uhh, let me try..

so you want FDA - BEF=?

let's divide this into 3 pieces:

ok, so A-F = -5 which means that we write down a "B" and substract an extra 1 at the next part

D-E-1 = -2, so we write down an "E" and an extra -1 at the last part.

F-B-1 = 3

so we have 3EB

FDA - BEF = 3EB

(To make it easier on yourself, you can substitute all the A's with 10's, the B's with 11's etc.... except in the solution)

Ok, number 2

A in base 16 is   10 in normal decimals

base 8 only goes till 7. so if you keep counting untill you've counted 10 numbers, you've got:

decimal: 7 ,8  , 9  , 10

base 8 : 7 ,10, 11, 12

so that A becomes a 12, write down the 2, remember the 1

the 9 becomes an 11, but with the 1 from that 12 it is another 12, so we've got:

22 (remember the 1)

the B becomes a 13, with the 1 it becomes a 14

422 (remember the 1)

that 1 stays a 1, with that last 1 it becomes a 2:

Answer:

1B9A hexadecimal is 2422 in base 8