Find the perimeter of the rectangle and the area of the rectangle?? Show all your work please

An appliance store sells a washer-dryer combination for $1800. if the washer costs $300 more than the dryer, find the cost for each appliance.

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a