Amy used 3 gallons of paint to cover 2,100 ft2 of wall space inside her house. how much wall space can she ain't with 7 gallons?

3gallons/ 2,100 ft = 7galloons/ X

3X= (2,100)(7)
X= (2,100)(7)/ 3
X= 4,900 ft^2

For 3 gallons, she used = 2100 ft²
so, 1 gallon, it will be = 2100/3 = 700 ft²

Now, for 7 gallons, it would be: 700 * 7 = 4900 ft²

So, your correct answer is 4900 ft²

Hope it helped.