Stacey and neil painted 280 ft2 of their living room wall with 4/5 gallons of paint. how many square feet can they paint with 3 gallons of paint?

Write and solve an equation of proportions.  4/5 gallon paint corresponds to 280 sq ft, and 3 gallons corresponds to an unknown area:

4/5 gall         280 sq ft
=
  3 gal                x

Then (4/5)x = 840 sq ft, so that x = (5/4)(4/5)x = (5/4)(840 sq ft)
                                                                          =1050 sq ft

These folks can paint 1050 sq. ft. with 3 gallons of paint.

Don’t know sorry girl