Question

PLEASE HELP VERY DESPERATE

Answer 1

You simply do the direct substitution,
you remove m and put the number of months given,
b=540-(30*9)= 270$
This example gives you an equation where calculates how much your balance is, an equation of b (balance) as a function of m (number of months), so simply substitute with the number of months given to you into the equation and you get the answer.
Hope this helps.

Answer 2

The answer is in the image
hope this helps