The area is 4(x+3). If we multiply the 4 out we have 4x + 12 as the area using the distributive property.
Expression: 4x+12
The original dimensions are x+3 and 4. If they are doubled, we have new dimensions 2x+6 and 8. The area is then 8(2x+6) = 16x + 48.
Area: 16x+48
Explanation: The ratio of the area of the original rectangle to the area of the larger rectangle is and will always be (4x+12)/(16x+48) = 1/4. Therefore, the ratio will be the same for any positive value of x.
