(a)

= 400
(b)


(c) Only the positive solution makes sense because you cannot have a negative side length.
(d) Since one side of the painting is 20 inches, all four sides together will be 20*4 = 80 inches
A. Standard form because there is only one digit in front of the decimal point.
Step-by-step explanation:
Ok so i looked on an app i hope helps(Im not really sure if this is correct)I hope you get it soon!
I think its c hope this helps sorry if it dont