Answer:
28 ft squared
Step-by-step explanation:
The 4 sides of a square are equal in length, so if the perimeter is 20ft that means each side would have to be 5ft, (20/4 = 5). If you increase the length by 2ft, one of the sides would now become 7ft (5+2 = 7). If you decrease the length of the other side by 1ft, the length would now be 4ft (5-1=4). Now to find the area, all you have to do is length * width. So you would do 7ft*4ft which is 28ft squared.
PEMDAS:
247/100 = 2.47
247* 100 = 24700
*You must ALWAYS apply the exponents first, THEN divide the equation.
18 kg times 5 kg would be 90 kg because each window was 18 kg, hence 90 kg
I think that the correct answer would be 6.
I hope that this helps you !