Ihave two problems that i need with. i'll attach them below.
can somebody me complete these?

1. Is $235,000+ 4.2% =244,870
4.2% out of $235,000 is $9,840
Where i got $244,870
12x20=240
So 20 years= 240 months
So I divide $244,870 by 240 months
is $1,020.291667
Which is $1,020.29 cents. 
If you multiply that $1,020.29x240=$244,869.60 round to nearest dollar 60 cents is over 50 which would make it $2444,870.