Factorise 3x to the power of 2 + xy

 x • (3x + y)

Step-by-step explanation:

Area of a rectangle is L * W
A = 12 * 18 = 216 ft^2

area of a triangle is : (h * b) / 2minus the area of the window L * W
A = (10 * 12) / 2 - (4 * 3) = 120/2 - 12 = 60 - 12 = 48 ft^2

216 + 48 = 264 ft^2 <== 
and if a gallon covers 70 sq ft264/70 = 3.77 gallons..rounds to 4 gallons

so ur answer is : A