That's easy, it is 126 divided by 6 equals 21 meters. cause the formula is base times height = area so you do the opposite of it which is base = area divide by height
The correct answer is : 30 ÷ (36 ÷ 4) = b, because 36 ÷ 4 represents how many days one bag lasts, we have 30 days in a month, so then 30 ÷ (36 ÷ 4) = b.