Plz help me thanks so much :( :)

Simplify a7/a4 a) 1/a3 b)-a/a2 c)a4/a3 d)a3

If your annual gross income is $62,000 and you have one monthly car payment of $335 and a monthly student loan payment of $225, what is the maximum house payment you can afford. consider a standard 28% front-end ratio and a 36% back-end ratio. also, to complete your calculation, the annual property tax will be $3,600 and the annual homeowner's premium will be $360.

Ineed with number 6 , explain how to get 1978